Last week, we covered the prospect hitters off to the best starts across the Minor Leagues. Next up: the pitchers.

No more guessing at how a mid-90s fastball will play at a certain level or if a plus slider will miss enough bats to be effective. We have one month of Minor League data to confirm just how good prospect arms can be in 2021.

These are some of the hottest pitching prospects to open the Minor League season, one for each organization:

AMERICAN LEAGUE EAST

Blue Jays: Alek Manoah, RHP (No. 5, MLB No. 96)
Put Wednesday’s outing aside, and recall that this is about the Minors. Few pitching prospects anywhere got off to the start that Manoah did with Triple-A Buffalo leading to his Major League debut. The 6-foot-6 right-hander posted a 0.50 ERA and 0.56 WHIP while fanning 27 in three starts (18 innings) at the top Minor League level, thanks to mid-90s heat and a promising slider and changeup. That stuff should keep Manoah in the Toronto rotation for the long haul.

Orioles: Grayson Rodriguez, RHP (No. 2/MLB No. 21)
No. 4 on our Top 10 RHP prospect list, Rodriguez made it clear that ranking might be light and that High-A ball was no match for him when he posted a 1.54 ERA over five starts, holding hitters to a .138 batting average while striking out 15.4 per nine (vs 1.9 BB/9). So up to Double-A he went and his first start at his new level on Thursday was much of the same: 5 IP, 4 H, 1 ER, 2 BB, 8 K.

Rays: John Doxakis, LHP (No. 29)
The 22-year-old left-hander is living up to his reputation as a control artist at Low-A Charleston but is doing more than just finding the zone too. Doxakis owns a 2.70 ERA and 0.71 WHIP with 38 strikeouts and only three walks over 26 2/3 frames to this point. It might be a bit of a conservative assignment for the 2019 second-rounder out of Texas A&M, but it’s promising nonetheless for Doxakis, who some believe is headed for a future relief role, to take off the way he has as a starter with the RiverDogs.

Red Sox: Brayan Bello, RHP (No. 18)
Bello displayed some of the best pure stuff in Boston's instructional league program last fall and has built on that momentum, going 4-0 with a 2.39 ERA, .223 opponent average and 36/7 K/BB ratio in 26 1/3 innings in High-A. Signed for just $28,000 out of the Dominican Republic in 2017, he has a mid-90s fastball and a pair of solid secondary offerings in his mid-80s slider and changeup.

Yankees: Ken Waldichuk, LHP (No. 27)
A fifth-round pick out of Saint Mary's in 2019, Waldichuk struck out 49 in 29 1/3 innings during his pro debut that summer and has been even more dominant in his first full season. Armed with a mid-90s four-seamer and a pair of solid breaking balls, he hasn't allowed a run in five High-A starts while permitting just eight hits and eight walks versus 38 strikeouts in 18 2/3 innings.

AMERICAN LEAGUE CENTRAL

Indians: Xzavion Curry, RHP (unranked on Indians Top 30)
A seventh-round pick out of Georgia Tech in 2019, Curry didn't make his pro debut until this spring because he had shoulder inflammation when he signed and the coronavirus pandemic wiped out the Minor League schedule last year. He's carving up Low-A hitters with the riding action on his 92-94 mph fastball, going 3-0 with a 1.07 ERA, .135 opponent average and 38/4 K/BB ratio in 25 1/3 innings.

Royals: Jackson Kowar (No. 4/MLB No. 98)
Kowar was named the Triple-A East Pitcher of the Month, and it isn’t hard to see why he was honored for his first month at the Minors’ top level. The 24-year-old right-hander, whose best pitch is his plus-plus changeup, has a 0.85 ERA and 0.88 WHIP with 41 strikeouts in 31 2/3 innings. His 1.94 FIP is the lowest among all qualified Triple-A pitchers. With the way Kansas City turns to young pitchers, Kowar’s time in the Majors can’t be far off.

Tigers: Angel De Jesus, RHP (unranked on Tigers Top 30)
It hasn’t been an easy start to the Minor League season for some of the bigger-named Tigers prospects, but don’t let that discount the job De Jesus is doing in relief for Double-A Erie. De Jesus, who can touch the mid-90s with a decent slider, has yet to allow an earned run while striking out 18 and walking five in 13 1/3 frames. His 35.3 percent K rate is highest among Detroit Minor Leaguers with at least 12 frames.

Twins: Matt Canterino, RHP (No. 7)
The Twins’ second-round pick out of Rice in the 2019 Draft, Canterino is making High-A look easy while the organization eases him into his first true full season. The right-hander has compiled just 18 innings over four starts, but has allowed just 10 hits (.154 BAA) and two earned runs (three total) while walking three and striking out 25. That’s an 11.67 K/BB ratio for those of you scoring at home.

White Sox: Jason Bilous, RHP (unranked on White Sox Top 30)
Part of Coastal Carolina's 2016 College World Series championship team, Bilous signed as a 13th-rounder two years later and demonstrated arm strength but spotty control in his first two pro seasons. He has issued just two walks in five starts between High-A and Double-A this spring, posting a 2.49 ERA with 33 strikeouts in 21 2/3 innings while working with a 93-95 mph fastball and solid curve.

AMERICAN LEAGUE WEST

Angels: Ryan Smith, LHP (unranked on Angels Top 30)
The Angels nabbed Smith in the 18th round of the 2019 Draft out of Princeton and he had a non-descript pro debut pitching in relief for rookie-level Orem that summer. Now starting for Low-A Inland Empire, Smith is making a claim for a promotion with a 1.66 ERA in four appearances (three starts), allowing just 12 hits over 21 2/3 innings (.160 BAA), walking six and striking out 37.

Astros: Jaime Melendez, RHP (unranked on Astros Top 30)
Signed for $195,000 out of Mexico in 2019, Melendez has an unconventional 5-foot-8, 190-pound build but owns a 92-95 four-seamer and a pair of hard breaking pitches. Making his full-season debut as a 19-year-old in Low-A, he sports a 0.60 ERA with a .115 opponent average and a 31/5 K/BB ratio in 15 innings.

A’s: Jack Weisenburger, RHP (unranked on A's Top 30)
Chosen as a potential future closer for the A’s recently, Weisenburger has been virtually unhittable coming out of High-A Lansing’s pen this year. A 20th-round pick out of Michigan in 2019, the right-hander has allowed just one run on five hits over 11 2/3 IP (0.77 ERA, .128 BAA), walking only two while striking out 23 for an astounding 17.7 K/9 ratio.

Mariners: Brandon Williamson, LHP (No. 10)
Williamson was a teammate at Texas Christian University with fellow southpaw Nick Lodolo (also in this story), now with the Reds. The 6-foot-6 Williamson, the Mariners’ second-rounder in 2019, has been outstanding with High-A Everett with a 2.25 ERA and .132 BAA in four starts, with 39 strikeouts in 20 IP. Take out one bad outing (4 2/3 innings, 4 ER) and he’s given up just one run on five hits over 12 2/3 IP.

Rangers: Jake Latz, LHP (unranked on Rangers Top 30)
Though Latz barely pitched in college at Louisiana State and Kent State because of elbow issues and NCAA transfer issues, the Rangers still selected him in the fifth round in 2017. They've brought him along carefully and he has succeeded with his 92-95 mph fastball and his slider, especially this year with a 1.96 ERA, .105 opponent average and 33/7 K/BB ratio in 23 Double-A innings.

NATIONAL LEAGUE EAST

Braves: Spencer Strider, RHP (No. 21)
The Braves’ fourth-round pick in the abbreviated 2020 Draft out of Clemson, Strider missed 2019 because of Tommy John surgery, but has shown velocity gains since coming back. Low-A hitters are clearly no match for him so far as he’s given up just one run (0.59 ERA) on six hits, walking five and striking out 32 in 15 1/3 IP (18.8 K/9). The Braves are understandably building him up slowly, but he didn’t give up that run until his fourth start of the year.

Marlins: Jake Eder, LHP (No. 24)
Eder flashed first-round stuff at Vanderbilt, where he saved the decisive game of the 2019 College World Series, but lasted four rounds last June because he was inconsistent with the Commodores. The Marlins challenged him with a Double-A assignment for his pro debut and he has responded by leading the Double-A South in ERA (0.73), opponent average (.135) and strikeouts (42 in 24 2/3 innings). He's blowing hitters away with a fastball that peaks at 98 mph and a power breaking ball.

Mets: Tylor Megill, RHP (No. 23)
New York execs had pointed to Megill as a potential breakout candidate prior to the 2021 season, and that has looked prescient thus far. The 25-year-old right-hander struck out 42 batters in 26 innings at Double-A Binghamton, leading to a 40.4 percent strikeout rate. He paired that with a 3.12 ERA and 1.08 WHIP in his five starts, using a plus fastball and breaking ball that he can shape to his needs. Megill was promptly promoted to Triple-A Syracuse this week.

Nationals: Cade Cavalli, RHP (No. 1/MLB No. 82)
The 2020 first-rounder was robbed of a chance to see the Minors last season and is taking full advantage of this opportunity to make a first impression. Cavalli is tied for third in the entire Minor Leagues with 45 strikeouts at High-A Wilmington, and he has needed only 27 2/3 innings to rack up that many. He has reached double digits in K’s twice so far through five starts, relying on a solid four-pitch mix to get there. Cavalli owns a 1.63 ERA and 0.98 WHIP while opposing batters are hitting only .198 against him. His status as the star of the Washington system has been solidified in the early going.

Phillies: Cristian Hernandez, RHP (No. 30)
Signed for $120,000 in July 2017, Hernandez has really stood out in his United States, and full-season, debut. The 6-foot-3 right-hander has a 2.01 ERA in 22 1/3 Low-A innings to date, allowing just 16 hits and only three walks (0.85 WHIP) while fanning 27 (9.0 K/BB ratio).

NATIONAL LEAGUE CENTRAL

Brewers: Ethan Small, LHP (No. 4)
One could point to Small’s 17 walks in 22 innings, and say he hasn’t been quite dominant. But it’s worth highlighting that the 24-year-old left-hander has been the starting pitcher in a Double-A Biloxi no-hitter on May 15 and that he is tied for third in Double-A Central with 38 strikeouts. Nick Lodolo, who is knotted with Small in K’s, has needed 4 2/3 more frames to reach that total in the same league. Small is also doing a good job of keeping runs off the board with a 3.27 ERA. If he can find the zone with slightly more regularity, his 2021 will be even more stellar.

Cardinals: Edgar Escobar, RHP (unranked on Cardinals Top 30)
A tough list to pick from here, but Escobar deserves mention for his work out of the Double-A Springfield bullpen. The 24-year-old right-hander has struck out 21 and walked only four over nine appearances (18 innings). He owns a 3.00 ERA and much-more-stellar 0.72 WHIP over that time as well. Escobar can throw in the mid-90s with a slider that generates swing-and-misses, and it’s notable that even left-handers are hitting only .100 against him.

Cubs: D.J. Herz, LHP (No. 28)
A North Carolina high school product with a projectable low-90s fastball and a sharp low-80s slider, Herz signed for fourth-round money ($500,000) in the eighth round of the 2019 Draft. He has surrendered just one earned run in his first four starts in Low-A, logging a 0.75 ERA, .081 opponent average and 20 strikeouts in 12 innings.

Pirates: Roansy Contreras, RHP (No. 20)
Teams always hope that new trade acquisitions will perform well so those deals look good. Contreras, acquired from the Yankees in January, is definitely holding up his end with Double-A Altoona, breaking out of the gate with 11 scoreless and 22 strikeouts in his first two starts, the second of which was a six-inning, no-hit performance. He’s only had one outing where he’s given up a run (4 IP, 5 ER on May 25), going 23 2/3 scoreless frames in his other four starts combined. For the year, he has a 1.63 ERA, .160 BAA, 0.76 WHIP to go along with 13.66 K/9 and 1.95 BB/9 rates.

Reds: Nick Lodolo, LHP (No. 1/MLB No. 46)
Lodolo and Hunter Greene have been a tremendous 1-2 punch in Double-A Chattanooga this year and either could’ve been the pick here. Lodolo has a 1.01 ERA (3 ER in 26 2/3 IP) to go along with a 0.825 WHIP in his five starts. He’s allowed just six hits for a .172 BAA while walking six and striking out 38 (12.8 K/9).

NATIONAL LEAGUE WEST

D-backs: Luis Frías, RHP (No. 9)
Frías got off to a killer start when he fanned 15 batters and allowed only one earned run over 11 innings in his first two starts at High-A Hillsboro. He was moved to Double-A Amarillo after that, and while his 4.82 ERA with the Sod Poodles doesn’t pop off the page, his 1.13 WHIP and 21 K’s in 18 2/3 innings are much more promising signs. The 23-year-old right-hander can reach the upper-90s and showcases a plus curveball that generates lots of whiffs. Expect the ERA to tumble as he gets more comfortable in Texas.

Dodgers: Cameron Gibbens, RHP (unranked on Dodgers Top 30)
A lanky 6-foot-8 Australian signed for just $10,000 in January 2020, Gibbens is making his pro debut and merited a promotion from Low-A to High-A four weeks into the season. Using a four-seam fastball that touches 98 mph and a low-80s slider, he has a 0.66 ERA, .170 opponent average and 28 strikeouts in 13 2/3 innings.

Giants: Caleb Kilian, RHP (No. 30)
A starter on back-to-back College World Series teams at Texas Tech, Kilian didn't allow an earned run in his 16-inning pro debut after signing as an eighth-rounder in 2019. He already has ridden his mid-90s fastball and hard curveball to a promotion from High-A to Double-A this year and has compiled a 1.40 ERA, .165 opponent average and 35/1 K/BB ratio in 25 2/3 innings between the two stops.

Padres: Ethan Elliott, LHP (unranked on Padres Top 30)
No one has added more fuel to their prospect stock in the San Diego system than Elliott. The 2019 10th-rounder was the High-A Central Pitcher of the Month after posting a 1.46 ERA and 0.69 WHIP with 38 strikeouts in 24 2/3 innings for Fort Wayne. His best outing came May 16 when he fanned 13 Lake County batters over six one-hit frames. Elliott’s bread-and-butter is his changeup, and his ability to command his three-pitch arsenal could keep the good numbers rolling into June.

Rockies: Will Ethridge, RHP (unranked on Rockies Top 30)
The Ole Miss product who was a fifth-round pick of the Rockies in 2019 has been very sharp in his full-season debut. Pitching for Low-A Fresno, the 6-foot-5 right-hander has posted a 2.10 ERA and allowed just 17 hits over 25 2/3 innings of work (.185 BAA). He’s been very stingy with walks, issuing only two while striking out 29 for an absurd 14.5 K/BB ratio.