Every season is an opportunity for a new batch of previously unknown or unheralded players to step into the spotlight, for young players to make a leap and for a select few to ascend to superstardom.

With 2020 coming to a close, we asked MLB.com's beat reporters to look ahead and name the top candidates to break out in '21. Here is one for every club.

American League East

Blue Jays: Nate Pearson, RHP
The hype surrounding Pearson’s arrival didn’t quite match Vladimir Guerrero Jr.’s from the year prior, but it was as close as you’ll see. The club’s No. 1 prospect struggled over his first five starts before going on the injured list with right elbow tightness, but he returned at the end of the year and delivered a fantastic two-inning relief performance in the playoffs.

Risks remain with Pearson, as they do with any pitching prospect, but his physical gifts on the mound are truly rare. While Pearson’s 100 mph fastball gets all of the attention, what has made him special coming through the Minor Leagues is his ability to use his excellent slider along with his curveball and changeup. As long as he’s complementing that heater and keeping opposing hitters off-balance, there’s a clear path for Pearson to pitch near the top of this rotation behind ace Hyun Jin Ryu.
-- Keegan Matheson

Orioles: Ryan Mountcastle, OF
Mountcastle, the Orioles' No. 5 prospect per MLB Pipeline, enjoyed a very productive 35-game debut in 2020, posting a .333/.386/.492 slash line. Any continuation of that would constitute a breakout. Easing Mountcastle’s transition is the lack of any erstwhile debate over his defensive home: He’ll be the O’s starting left fielder on Opening Day, and all he needs to do to stay there is hit. If his track record is any indication, that shouldn’t be a problem.

The 23-year-old Mountcastle hit at every level prior to his promotion last summer, winning International League MVP honors at Triple-A in 2019 on the strength of his bat. Additionally, he should have protection in the middle of the O's lineup, surrounded by 2020 breakout star Anthony Santander and the returning Trey Mancini.
-- Joe Trezza

Rays: Yoshi Tsutsugo, 3B/OF
Tsutsugo’s first season in the big leagues didn’t go as planned, but it’s hard to imagine a more difficult transition than the one the Japanese slugger had to experience last season. Getting acclimated to a different culture and routine is challenging all in itself, but Tsutsugo also had to deal with the stoppage and an abbreviated Summer Camp, which undoubtedly limited his progress. But despite a disappointing season, Tsutsugo showed signs of the player that the Rays signed to a two-year, $12 million deal last offseason.

Tsutsugo finished in the 73rd percentile in exit velocity, and his hard-hit rate was in the 86th percentile. He also displayed the ability to put together good at-bats, finishing in the 87th percentile in walk rate and in the 66th percentile in whiff rate. Tsutsugo is expected to get more opportunities in 2021, and his eight home runs in 157 at-bats last season are a good indicator that his power can certainly translate to the Majors.
-- Juan Toribio

Red Sox: Bobby Dalbec, 1B/3B
The Red Sox got a glimpse of their No. 3 prospect’s plus raw power in 2020, when Dalbec hit .263/.359/.600 with eight homers in 23 games after Mitch Moreland was traded to the Padres. There is swing and miss in his game (42.4 percent strikeout rate), but the pop is real.

After garnering Kris Bryant comparisons coming out of the Draft, Dalbec hit 59 home runs over his final two Minor League seasons. He’ll get his chance to tap into that every night in Alex Cora’s lineup, whether it's at first base or his natural position of third.
-- Ian Browne

Yankees: Michael King, RHP
King benefited from his time at the Yankees' alternate training site this past summer, where he huddled with pitching coordinator Sam Briend to refine the axis of his changeup, giving it a different profile than his fastball. The right-hander saw results in the AL Division Series, retiring all six Rays he faced in a Game 3 relief appearance.

King has also changed his slider into a curveball, tinkering with improvements that he believes will help him secure a rotation spot in 2021.
-- Bryan Hoch

AL Central

Indians: Nolan Jones, 3B
He may not see much time at the hot corner in 2021, but Jones, the Tribe’s No. 1 prospect according to MLB Pipeline, could get a chance to make a significant impact with the club. With José Ramírez at third base, the Indians have asked the 22-year-old Jones to practice at first base and in the outfield.

Jones spent the 2020 season at the Tribe’s alternate training site after hitting .272 with an .851 OPS, 15 homers, 63 RBIs, 148 strikeouts and 96 walks in 126 games in ‘19. He may start '21 in Triple-A, but Jones is likely to make his debut next season and could be the spark that has been missing from Cleveland’s offense.
-- Mandy Bell

Royals: Adalberto Mondesi, SS
Over his final 22 games in 2020, Mondesi showed what a dangerous player he can be when his full skill set is on display. In that span, he hit .376 with a 1.130 OPS and had six doubles, two triples, six home runs and 19 RBIs. Mondesi also stole 16 bases and played elite-level defense.

This is the player the Royals have been touting for years, and if he can put it all together for an entire season, the 25-year-old Mondesi will emerge as one of the best players in the Majors.
-- Jeffrey Flanagan

Tigers: Tarik Skubal, LHP
Skubal's numbers from his first big league callup weren't impressive, but that's understandable, considering he missed all of Summer Camp and made just a few starts at the Tigers' alternate training site before his debut. The lanky left-hander showed promise in his final three starts, recording 20 strikeouts and allowing just 10 hits over 14 2/3 innings as he grew comfortable throwing all his pitches to top-level competition.

Skubal might open the season at Triple-A Toledo to control his innings total, but with a full Spring Training and a chance to work with new Tigers pitching coach Chris Fetter, he should look more like the dominant pitcher who vaulted up prospect rankings in 2019.
-- Jason Beck

Twins: Jorge Alcala, RHP
Alcala was eased into regular action in 2020 after everyone from manager Rocco Baldelli to special assistant LaTroy Hawkins noted that the 25-year-old right-hander particularly impressed them in camp. Though Alcala didn’t pitch in the highest-leverage situations, he made an impact with a 2.63 ERA, 27 strikeouts and eight walks in 24 innings spanning 16 appearances.

It’s easy to tell why the Twins like his stuff so much: Alcala’s slider averaged 88.6 mph last season, with a 38.9 percent whiff rate, and he was the only Twins pitcher to throw a pitch harder than 100 mph in 2020. With Sergio Romo, Tyler Clippard, Trevor May and Matt Wisler all gone from the Twins’ relief corps, the team needs someone to step up alongside Taylor Rogers and Tyler Duffey in the late innings. Alcala could be that guy.
-- Do-Hyoung Park

White Sox: Andrew Vaughn, 1B
Vaughn, the No. 1 White Sox prospect and No. 13 prospect overall per MLB Pipeline, looked Major League ready during his time at big league camp in Arizona. The reports also were excellent regarding Vaughn’s work with the bat at the team’s alternate training facility in Schaumburg, Ill., to the point where Vaughn became virtually untouchable in trade talks and almost was called up during the abbreviated 2020 campaign.

Vaughn could become the White Sox designated hitter for much of the 2021 season, which will be an adjustment for a 22-year-old accustomed to regularly playing the field. Vaughn hasn't played above Class A Advanced in the Minors, but the team’s top pick in the 2019 Draft has the skill set to take off immediately.
-- Scott Merkin

AL West

Angels: Jo Adell, OF
Adell struggled as a rookie in 2020, but the 21-year-old has the talent to bounce back in ‘21. Adell, the club’s best prospect since Mike Trout, has all the tools needed to make his presence felt at the MLB level, with power, speed and a solid throwing arm. Trout also had a tough time in his first taste of the Majors, so it’s not anything unique to Adell.

While manager Joe Maddon told reporters earlier this month that Adell "needs more time in the Minor Leagues, no question," he will likely get a chance to win the starting job in right field during Spring Training. He’ll be pushed by Taylor Ward, who is coming off a surprisingly solid year offensively and is likely to be the club’s fourth outfielder if Adell wins the job.
-- Rhett Bollinger

Astros: Enoli Paredes, RHP
Paredes was one of 10 promising young arms to make his Major League debut for Houston last season, when injuries decimated the Astros’ pitching staff in a shortened season. Almost immediately, the wiry Paredes became a trusted late-inning option for manager Dusty Baker.

Relying mostly on a 95.7 mph four-seam fastball and an 85.5 mph slider, which produced a 46.3 percent whiff rate, Paredes posted a 3.05 ERA and struck out 20 batters in 20 2/3 innings across 22 relief outings. If he can refine his control -- he averaged 4.8 walks per nine innings -- he’ll be one of the Astros’ top high-leverage options out of the bullpen again in 2021.
-- Brian McTaggart

Athletics: Sean Murphy, C
The A’s believe they have a perennial All-Star behind the dish in Murphy, and if the way he ended the 2020 season is any indication, the 26-year-old catcher may just be scratching the surface of stardom. Not only did Murphy show off his cannon of an arm behind the plate, but the rookie also finished the season as Oakland’s best hitter, leading the club in OPS (1.062) and home runs (five) over the final month of the regular season as he slashed .277/.424/.638 across 16 games in September.

Showing the ability to handle a heavy workload coming off left knee surgery in 2019, Murphy will become a mainstay in the middle of the A’s lineup next season.
-- Martín Gallegos

Mariners: Evan White, 1B
While White already has impressed defensively, becoming the first rookie first baseman to win a Gold Glove Award, he posted a .176/.252/.346 slash line with eight homers and 84 strikeouts in 202 plate appearances during his first season in the Majors.

It’s worth remembering, however, that the 2017 first-round Draft pick was making the jump straight from Double-A ball. Plus, White had the top average exit velocity, hard-hit rate and barrell rate on the club. If the 6-foot-3, 220-pound slugger relaxes and plays his game, he could be a big part of the Mariners’ lineup as well as a defensive standout for years to come.
-- Greg Johns

Rangers: Nick Solak, 2B
After hitting .293/.393/.491 with five home runs over 33 games in 2019, Solak dropped to .268/.326/.344 with two homers across 58 games in '20. But he is going to get a chance to be the Rangers' everyday second baseman next season. After bouncing between second and the outfield, the hope is that settling into one position will allow the 25-year-old to flourish offensively.

Rougned Odor has been the Rangers' starting second baseman over the past seven seasons, but his offense has fallen off and Texas is eager to see what Solak can do given the chance to play regularly.
-- T.R. Sullivan

National League East

Braves: Austin Riley, 3B
Having struggled over the final three months of his 2019 rookie season and the final three weeks of this year’s shortened season, Riley had left reason to question his future. But when the 23-year-old slugger hit his decisive ninth-inning homer off Blake Treinen in Game 1 of this year’s NL Championship Series, he provided a reminder of his tremendous power potential.

After Riley homered once every 11.8 at-bats through his first 43 career games, pitchers constantly had him chasing sliders off the plate. He fared much better against breaking balls this year and seemed to find a groove just before his hamstring began bothering him in early September. The jury is still out on whether he’ll live up to expectations. But he showed enough improved plate discipline this year to believe he could break out and provide more consistency in 2021.
-- Mark Bowman

Marlins: Jazz Chisholm, 2B/SS
Chisholm got a taste of the big leagues in 2020, appearing in 21 games. For the most part, the energetic 22-year-old shortstop endured some growing pains, batting .161 with a .563 OPS in 62 plate appearances. But by the time the playoffs rolled around, Chisholm was starting to scratch the surface of his immense potential.

Ranked by MLB Pipeline as Miami’s No. 4 prospect and the 61st prospect overall, Chisholm is expected to compete for the starting second-base job in 2021. Even though he projects as the shortstop of the future, Chisholm is athletic enough to play second and perhaps even center field, and his elite bat speed, power and speed could make him a multidimensional threat.
-- Joe Frisaro

Mets: Sam McWilliams, RHP
Outside of players coming from foreign leagues, it had been over a decade since a team offered a big league contract to a free agent with zero Major League experience. There’s a reason why the Mets broke that trend with McWilliams, outbidding half the league with their $750,000 agreement. They believe that the right-handed McWilliams, whose velocity has reached the upper 90s, can provide depth for both their rotation and bullpen.

No matter what McWilliams’ role ultimately is, he’s likely to receive significant time in the Majors after reaching Triple-A in 2019 and spending last summer working at the Rays’ alternate site. That gives him a chance to make a difference for the Mets.
-- Anthony DiComo

Nationals: Joe Ross, RHP
Ross emerged as a top contender for the open fifth starting spot in 2020 before he elected not to play this past season. After splitting the role in previous years, the right-hander is hungry to land a full-time spot in the rotation when he returns in ‘21. Manager Dave Martinez would like him to achieve that, as well.

“I want Joe to be in the rotation,” Martinez said last week. “He’s got every opportunity in the world -- whether it’s the fifth starter, whether it’s the fourth starter, who knows -- but he’s going to get every opportunity to do that.”

Ross most recently went 4-2 with a 3.02 ERA across nine starts in 2019. (He also appeared in 18 games out of the bullpen.) That postseason, he made a memorable spot start for an injured Max Scherzer in Game 5 of the World Series on short notice.
-- Jessica Camerato

Phillies: Connor Brogdon, RHP
If you hadn't heard, the Phillies' bullpen was historically bad in 2020. They need to start fresh, but they have a few returning pieces that could help them, including Brogdon. The righty struggled early on last season and was optioned in August, but he returned in September and dominated, striking out 14 batters and walking two in 8 2/3 scoreless innings.

Brogdon did it with a fastball that averaged 95.3 mph and a fantastic changeup. He also mixed in a cutter. The whiff rate on all three pitches skyrocketed in September compared to August. If Brogdon’s final month is a sign of things to come, he could become a key back-end piece to the bullpen, much like former setup man/closer Ryan Madson.
-- Todd Zolecki

NL Central

Brewers: Luis Urías, INF
Whatever could go wrong for Urías in 2020 did. Acquired with high expectations alongside lefty Eric Lauer in a Thanksgiving trade with the Padres, Urías was supposed to compete with Orlando Arcia to be Milwaukee’s starting shortstop. But Urías was denied that opportunity when he sustained a broken hamate bone in his left hand and missed the first three-plus weeks of Spring Training. The day he was supposed to make his Cactus League debut, baseball paused due to the coronavirus pandemic. And when the game started up again in July, Urías was sidelined again by a positive COVID-19 test.

When he finally did get into games for the Brewers, Urías slashed a solid .297/.366/.378 over his first two weeks before fading the rest of the way. One can argue that no player on Milwaukee’s entire roster could benefit more from a healthy, uninterrupted season than Urías, who figures to once again compete with Arcia at shortstop.
-- Adam McCalvy

Cardinals: Dylan Carlson, OF
The club’s No. 1 prospect struggled some when he first debuted in the Majors last summer, but he really showed what he could do during the Cardinals’ Wild Card Series against the Padres, when he had a 1.016 OPS across three games and 14 plate appearances as the cleanup hitter. The Cardinals expect to see more of that from the switch-hitting outfielder, and he’ll get a chance to make good on those expectations in 2021.

Carlson, who also impresses with his defense, is set to compete for a starting job in Spring Training and will likely see playing time all over the outfield next season. He’s not the sole fix for the Cardinals' offense, but allowing Carlson to experience a full season will set him -- and the Cardinals -- up well for the present and future.

“I’m excited,” Cardinals manager Mike Shildt said last week. “This guy’s got a lot of good skill sets. He’s good at pretty much everything he does and is only going to continue to get better. He’s a hitter, which I like. He can hit. The power will be there, and he’ll do some damage.”
-- Anne Rogers

Cubs: Adbert Alzolay, RHP
There will be at least one vacancy in the Cubs’ rotation come Spring Training, and the 25-year-old Alzolay will be a leading candidate to claim a spot. The right-hander (No. 6 on MLB Pipeline’s Top 30 Cubs prospects list) has had a handful of stints in the big leagues in the past two years. Last season, Alzolay spent a lot of time at the Cubs’ alternate site, where he worked to add a slider that impressed in his two September outings in the Majors. In those games (one start and one four-inning relief appearance), Alzolay struck out 15 batters, walked four and allowed four hits and two runs in nine innings. He generated 15 whiffs out of 34 swings against his breaking ball. After finishing with a 2.95 ERA and 29 K's in 21 1/3 innings overall, Alzolay will have a real shot at stepping forward as a reliable rotation piece in 2021.
-- Jordan Bastian

Pirates: Quinn Priester, RHP
You won’t see Priester in Pittsburgh in 2021. You might not even see the right-hander, the Pirates’ first-round pick in the 2019 Draft, pitch at PNC Park in '22. But Priester very well could appear on MLB Pipeline’s preseason top 100 prospects list, and the Bucs believe their No. 4 prospect is going to turn some heads in the Minors during his first full season of professional baseball. Pirates officials say Priester has an advanced repertoire and maturity beyond his years, an exciting combination of raw talent and intelligence, but he just hasn’t had many chances to show it all yet.

Priester only made nine appearances after signing with the Pirates in 2019, going 1-1 with a 3.19 ERA and 41 strikeouts over 36 2/3 innings in the lower Minors. Priester, who turned 20 in September, spent a little less than a month at the Pirates’ alternate training site before reporting to their instructional league camp in Bradenton, Fla. During one outing against a group of Phillies prospects, Priester’s fastball sat around 97 mph for three innings and touched 99.
-- Adam Berry

Reds: Tyler Stephenson, C
The 24-year-old Stephenson, Cincinnati’s No. 4 prospect and MLB's No. 96 prospect overall per MLB Pipeline, impressed at the club's alternate site and during his limited big league opportunities in 2020. He went 5-for-17 (.294) with two home runs -- one in his first game on July 27 and a walk-off two-run shot against the Pirates on Sept. 14. Stephenson has also made improvements with his defense and game calling. With veteran Curt Casali being non-tendered, the right-handed-hitting Stephenson will likely be paired with lefty-hitting veteran Tucker Barnhart in '21.

“He stepped in last year and got some good experience, had some success,” Reds manager David Bell said. “He’s really developed. He’s matured just, kind of, right in front of your eyes the last couple of years. He’s going to get some playing time for sure. He stepped in last year and got some good experience, had some success. He’s really developed … He’s ready. And I think having the combination of him and Tucker is a nice situation to have.”
-- Mark Sheldon

NL West

D-backs: Zac Gallen, RHP
Gallen’s 2020 season didn’t get much national attention because the D-backs fell out of the playoff chase early, but he did manage to make history. Continuing a streak he started in '19, Gallen became the first pitcher to begin his career with 23 straight starts in which he allowed three runs or fewer. After compiling a 2.89 ERA in eight starts for Arizona in '19, Gallen finished with a 2.75 ERA in '20. If you take out a pair of consecutive innings in which he allowed a total of eight runs -- the sixth on Sept. 7 and the first on Sept. 12 -- his ERA would have been 1.77 and he likely would have finished higher than ninth in the NL Cy Young Award voting. At just 25, Gallen is only beginning to scratch the surface of his potential.
-- Steve Gilbert

Dodgers: Victor González, LHP
The “other” left-handed teenager signed by the Dodgers when they discovered Julio Urías in Mexico in 2012, González dropped off the radar after missing '17 while recovering from Tommy John surgery and nearly walking away from the game. It took seven Minor League seasons for González to reach Double-A, but his big league arrival in '20 was spectacular, with 23 strikeouts and two walks in 20 1/3 regular-season innings and eight clutch postseason appearances. As the Dodgers try to repeat as World Series champions, González figures to have a prominent role, either as a lefty out of the bullpen or in the rotation, where Los Angeles has lingering uncertainty after David Price sat out '20 because of COVID-19 concerns.
-- Ken Gurnick

Giants: Joey Bart, C
Bart underwhelmed after making his highly anticipated Major League debut in August, but the 24-year-old catcher should be better positioned to succeed in 2021, with the expected return of Buster Posey and the Minor League season. As Evan Longoria pointed out in September, Bart likely was hurt by the absence of Posey, who was unavailable to offer his tutelage after electing to sit out the '20 campaign. Bart is likely to open next season at Triple-A Sacramento to further his development, but if he can refine his plate discipline -- he racked up 41 strikeouts and only three walks in '20 -- and show that he can elevate the ball more consistently to leverage his power, he has the potential to succeed Posey and become the Giants' next star catcher.
-- Maria Guardado

Padres: MacKenzie Gore, LHP
There should be opportunity for Gore to finally make his mark on the Padres' rotation in 2021. MLB Pipeline's top pitching prospect, Gore has been one of the Minors' most dominant arms since '17. He spent the '20 season at the team's alternate training site, but he seems primed for a breakthrough in '21. The Padres could sure use it, considering the vacancy at the back end of their starting rotation. Sure, they seem poised to add Blake Snell. But Mike Clevinger is out for the year following Tommy John surgery, and Luis Patiño is headed to Tampa Bay in the Snell deal. The Padres would love to see Gore step up and earn the final place in their rotation next spring. If he does, he might stay there for a long time.
-- AJ Cassavell

Rockies: Ben Bowden, LHP
The Rockies could have used Bowden last year, but he sustained a back injury during Spring Training and never was healthy enough to be called to the Majors. Going back to 2019, Bowden shined brightly with Double-A Hartford, recording a 1.05 ERA, 20 saves and 42 strikeouts in 25 2/3 innings. Injuries have been an issue since he was selected in the second round of the 2016 MLB Draft. But if Bowden can stay healthy, the Rockies could have a sorely needed lefty at a low cost.
-- Thomas Harding