Players who blossomed after rough debuts

Players who blossomed after rough debuts

Some of game's brightest stars endured big league growing pains

May 13th, 2022

The Mariners optioned to Triple-A Tacoma on Friday, marking the second time the outfielder has been sent back to the Minors since he made his big league debut in 2021.

Kelenic was MLB Pipeline's No. 4 overall prospect when he received his first callup in May 2021, and his Minor League production was stellar. But his career hasn't gone the way anyone had hoped.

Through 473 plate appearances with Seattle, Kelenic has put up a .173/.256/.338 slash line with 17 homers and 142 strikeouts.

Kelenic is far from the first hyped young player to fall flat early on. That said, many of those prospects rebounded and showed why scouts were so high on them in the first place. Kelenic himself showed flashes last September after getting called back up, putting up an .854 OPS with seven homers in his final 29 games.

Here's a look at some recent stars who initially failed to deliver on expectations before putting it all together. Let these players serve as a reminder that the 23-year-old Kelenic could yet blossom into the player many expected.


Giolito recovered from Tommy John surgery to become MLB’s top pitching prospect by his 2016 debut. But the Nationals dealt Giolito to the White Sox after just six uneven outings, and he posted the American League’s worst qualified ERA (6.13) in his first full season in ‘18.

Then, Giolito surged after making mechanical adjustments before the 2019 season, striking out 228 hitters and finishing sixth in that year’s AL Cy Young Award vote. In ‘20, he became the first White Sox pitcher to record a no-hitter with 10 or more strikeouts, and he had another strong year in '21.


The Red Sox signed Moncada to a record-shattering $31.5 million international signing bonus in 2015, and MLB Pipeline ranked him as baseball’s top prospect, billing him as “Robinson Canó with more speed.” Then Moncada struck out in 12 of his first 20 big league plate appearances, and Boston dealt him to the White Sox in a blockbuster trade for Chris Sale.

Moncada struggled on both sides of the ball with Chicago, striking out a Major League-most 217 times in 2018, before finally breaking out the next year. A position change from second to third base yielded big dividends, as did a more aggressive plate approach that saw him post a 140 OPS+.


MLB Pipeline ranked Judge as the Yankees’ No. 4 prospect in a wave that included Clint Frazier, Gleyber Torres and Miguel Andújar, but the hulking 6-foot-7, 280-pounder found trouble timing his long levers to big league pitches in 2016, striking out in half of his 84 at-bats. That all changed in a mythical ‘17 campaign, when Judge walloped a rookie-record 52 home runs (since surpassed by Pete Alonso), challenged Giancarlo Stanton for many of Statcast’s exit velocity and home run distance records and finished runner-up to Jose Altuve in the AL MVP Award vote. He has been the Yankees’ clubhouse leader ever since.


Gallo still strikes out a ton and hasn't been all that productive since he was traded from the Rangers to the Yankees in July 2021, but he’s certainly a more finished product now than the free-swinging prospect who struggled to a .173 average and nearly 50% strikeout rate across his first 53 big league games with Texas between 2015 and ‘16. Gallo's career batting average is barely above the Mendoza Line, but he recorded 151 homers, 341 walks and a 117 OPS+ from 2017-21. He's also become a strong defensive outfielder -- winning back-to-back Gold Glove Awards in 2020-21 -- after bouncing around the diamond earlier in his career.


Berríos became the highest-drafted pitcher out of Puerto Rico when the Twins took him with the 32nd overall pick in 2012, and he was MLB Pipeline’s fourth-ranked right-hander in ‘15. But injuries to the Twins’ rotation the following year forced Berríos into big league action before he was ready, and he struggled mightily (8.02 ERA, 5.4 walks per nine innings) across 14 starts. The righty eventually found his footing and posted a 3.74 ERA with a 9.2 K/9 from 2017-21, including a 3.58 ERA with a 10.0 K/9 over 12 starts following a July 2021 trade to the Blue Jays.


Berríos’ brother-in-law was also a high draft pick out of Puerto Rico, and he ascended to a top 10 overall prospect with heralded bat speed (which he showed off against Giolito in the 2014 All-Star Futures Game). But Báez whiffed a ton against big league pitching after his ‘14 callup (95 strikeouts in 213 at-bats), requiring more Minor League seasoning for much of ‘15 before he came up and helped the Cubs reach that year’s NLCS.

Of course, “El Mago” became a key contributor to Chicago’s curse-breaking ‘16 World Series champions, and he improved even further to finish runner-up in the NL MVP Award voting in ‘18.


The Aruba native reached Double-A at age 19 and ascended to MLB Pipeline’s No. 6 overall prospect by 2013, the year he made his big league debut with the Red Sox. Bogaerts earned some starts toward the end of Boston’s run to the World Series championship, but he didnt live up to sky-high expectations as the club’s starting shortstop in ‘14, striking out 138 times and struggling with the glove. He rebounded to hit .320 the following year and earned an All-Star selection in ‘16.


Twenty-four players were, famously, selected before Trout in the 2009 MLB Draft, but the center fielder's preternatural talent quickly became evident enough to make him baseball’s No. 1 prospect. Everyone remembers how Trout cashed in on that promise and put up one of the greatest Rookie of the Year Award campaigns in ‘12, but don’t forget that, if only for a brief moment, Trout actually struggled in the bigs. He finished his first 40-game cup of coffee with a mortal .220/.281/.390 batting line, hitting just five homers in 123 at-bats.


Rizzo overcame a Hodgkin’s lymphoma diagnosis to become the jewel of the Red Sox’s farm system. Then, Boston packaged him as the centerpiece prospect in a trade to the Padres for Adrián González. He kept on tearing up Minor League pitching, but he couldn’t translate that to The Show, batting just .141 with one homer across 153 plate appearances in his only season with San Diego. Another trade sent him to Chicago, where it took him another two years before he earned his first All-Star Game nod.


Upton’s easy athleticism drew comparisons to Ken Griffey Jr. as the D-backs made him the top overall Draft pick in 2005, but he got off to an underwhelming start two years later, recording a 62 OPS+ and then drawing some controversy with a hard slide in the ‘07 NLCS. Upton didn’t really come into his own until '09, when he hit .300, paired 30 doubles with 26 homers while stealing 20 bases.


The second overall pick behind Upton in 2005 was the Royals' savior-in-waiting after many K.C. seasons in the AL Central cellar. But after picking up both the Golden Spikes Award at Nebraska and Baseball America’s Minor League player of the year honor at Double-A, Gordon largely didn’t thrive until ‘11, when he hit .303 and clubbed 45 doubles. Of course, the recently retired Gordo eventually became a key piece of the Royals’ World Series championship club in 2015 and a franchise icon.


Baseball America ranked the Florida southpaw among both the Phillies’ and White Sox top prospects, but he didn’t pitch for either team before he was eventually traded to the A’s. Success was harder to come by in the Majors than the Minors for González, who owned a 6.24 ERA after his first 30 big league appearances before flipping the switch for an excellent 2010 season (15 wins, 200 2/3 innings, 3.23 ERA) with Oakland.


Petey’s back-to-back AL Rookie of the Year and MVP seasons in 2007 and ‘08 are the stuff of legend in Boston, but his first 31-game cup of coffee in ‘06 is rarely discussed. Pedroia, who was ranked as high as 11th overall on Baseball Prospectus’ Top 50 prospect list, slashed just .191/.258/.303 (42 OPS+). But in a sign of things to come, he also struck out just seven times.


Tulo needed only 126 games in the Minors before the Rockies called him up, and he would parlay his awesome rookie 2007 season into a six-year, $31 million contract extension after just one year and 33 days of service time. But wedged in between those two achievements was a largely forgettable 25-game cup of coffee that saw Tulowitzki struggle to a 53 OPS+ and one homer in 96 at-bats.


A-Rod still frequently comes up in statistical queries for the best starts to any big league career. But while his age-20 season (.358 BA, 54 2B, 36 HR, 9.2 fWAR) remains insane more than 25 years later, even he had some growing pains. His age-18 and -19 seasons saw him combine for a 56 OPS+ and only five homers and seven steals across his first 65 career games.