Recent seasons have seen a bunch of exciting new aces make the leap, like Dinelson Lamet and Corbin Burnes in 2020 and Shane Bieber and Lucas Giolito in 2019. Let’s figure out who might be next.
MLB.com convened five reporters to draft 10 breakout pitcher candidates for the coming season — five from the American League and five from the National League. We were looking for pitchers who are young (27 or under), have pitched in the Major Leagues already (so no MacKenzie Gore) but have yet to put up any ace-like numbers in their careers to date.
Casey Mize — RHP, Tigers
Key number: +5.3 inches of splitter drop vs. avg.
Mize’s 6.99 ERA in 2020 is not what you want, but we’re betting on his nasty stuff to emerge in full force in 2021. The No. 11 prospect in baseball just needs to make a few adjustments and he can be an ace.
Step 1: Unleash his signature splitter, which has the second-best drop of any splitter in the Majors.
Step 2: Attack the strike zone vertically, going up and down with his fastballs, splitters and sliders along the same vertical plane as opposed to across the plate horizontally. (Mize is already planning to do this.)
Step 3: Stop wasting so many pitches and command the edges of the zone. That is the recipe for success.
— David Adler
Jesús Luzardo — LHP, A’s
Key number: 45% whiff rate on curveballs and changeups
The 23-year-old left-hander has made nine career starts, all in 2020, when he posted a 4.12 ERA (101 ERA+). But if you take out two poor starts, in each of which he gave up four runs over 4 2/3 innings, you get a 2.93 ERA as a starter. Luzardo misses bats at a high rate — hitters missed on 45.7% of swings against his curveball last year, and the whiff rate for his changeup, which has a differential of around 8-10 mph off his 96 mph fastball, was 44.5%.
Luzardo also has solid control, finishing in the 72nd percentile among qualified pitchers in 2020 with a 6.9% walk rate. And if you go back a couple of years, you see that Luzardo posted a 2.53 ERA over three Minor League seasons, moving through the Washington and Oakland systems rapidly at a young age. There’s nothing to suggest he’s not primed for a big season in 2021.
— Manny Randhawa
Tarik Skubal — LHP, Tigers
Key number: 94.4 mph avg. velocity / 2,422 rpm avg. spin rate on fastball
Skubal debuted a day before his fellow Tigers pitching prospect Mize last August, so it’s fitting both young rotation-mates are featured here. After rocketing up prospect lists in 2019 while racking up 179 strikeouts in 122 2/3 innings (13.1 K/9), Skubal flashed his electric stuff at times in The Show in 2020. Overall, though, the 6-foot-3, 215-pound lefty was inconsistent and homer-prone (2.5 HR/9), finishing with a 5.63 ERA in eight outings (seven starts).
Still, it was an extremely small sample (32 innings), and there were signs that Skubal — the No. 24 overall prospect in baseball — will succeed, including striking out more than a batter per frame. That can be attributed in part to his impressive fastball velocity and spin rate: Skubal’s average four-seam velo of 94.4 mph ranked fourth among lefty starting pitchers, sandwiched between Blake Snell and Julio Urías, and his average fastball spin rate of 2,422 rpm was in the 82nd percentile of MLB.
If Skubal can elevate the heater and bury his plus slider glove-side more routinely, especially against lefty hitters, he should get plenty of whiffs and be more difficult to square up. The big challenge will be proving his changeup can counter right-handed bats, which posted a .905 OPS and hit all nine homers off Skubal. He did show he could handle opposite-side hitters in the Minors in ’19 (.180/.259/.304 slash line), so the ability is there. So is the potential for Skubal and Mize to find their footing and flourish together in Detroit.
— Jason Catania
Canning may very well have been on his way to a breakout season in 2020 had it not been for the abbreviated campaign. After a bit of a slow start, the right-hander put up a 3.14 ERA over his final five starts, capped by the best outing of his young career — holding the Padres’ potent offense to one run on two hits over six innings while racking up a career-high 10 strikeouts.
Canning’s revamped curveball was on full display in that dominant performance against San Diego, providing a glimpse of what could allow the 24-year-old to take his game to the next level. He altered his curveball grip last season to make it dive a bit more — and it produced results. Canning’s curve induced a whiff rate of 47.1% in 2020, a big improvement from 34% in ’19. In fact, here’s the full list of starting pitchers to work at least 40 innings last season and register a higher curveball whiff percentage than Canning: Blake Snell, Tyler Glasnow, Shane Bieber and Gerrit Cole. Not bad company.
Not surprisingly, the curveball became Canning’s go-to secondary pitch last season. After relying more on his slider (28.9% of his pitches) than his curveball (16%) in his debut season in 2019, Canning turned more to the revamped curve (22.9%) than his slider (20.7%) last season. Don’t be surprised if that curveball percentage creeps up even more in ’21, especially if it continues to get the results it did down the stretch.
— Paul Casella
Nate Pearson — RHP, Blue Jays
Key number: 37% whiff rate on secondary pitches
A thrilling July debut devolved into a growing-pains summer for Toronto’s next big thing, and there wasn’t much fluky about Pearson’s sky-high 16% walk rate. The righty was among 2020’s worst starters by STATS’ Command+ metric, which attempts to judge how well a pitcher located the pitch he intended to throw. But Pearson also flashed a lot of the tools one wants to see from a top prospect.
Obviously there was the ability to hit triple digits on the radar gun. But we’re just as intrigued by his secondary pitches: a slider with good depth, a big loopy curve and a high-80s changeup that could be unfair after hitters see the heat. Pearson is going to have to diversify as hitters get more looks at him, but each of those secondary pitches racked up 30-plus percent whiff-per-swing rates. Better yet, Statcast gives him one heck of a comp list based on the velocity and movement of his arsenal.
Pearson still has a lot to refine, and he has to prove that he can endure 30 starts. But we’re betting heavily on that skillset.
— Matt Kelly
Trevor Rogers — LHP, Marlins
Key number: 30% strikeout rate + 46% ground-ball rate
Set aside that 6.11 ERA for a moment (and, really, 2020 ERA means even less than usual). Rogers pumped up his fastball velocity for his MLB debut, touching 96 mph from the left side, and that heater popped from his easy, breezy delivery. Rogers’ slider and changeup missed bats, too, helping him finish his first campaign with a 30% strikeout rate.
That’s a great number, but what’s more impressive is he paired it with a near-50% ground-ball rate; very few starters can be elite in both categories at once. In fact, Rogers is one of only eight rookie starters to pair a 10.0 K/9 rate with a 45% grounder rate dating back to 2010, and he’s in great company alongside names like Stephen Strasburg, Yu Darvish, Max Fried and Ian Anderson. We’re bullish on the vibes from Miami’s young rotation as a unit, and that includes Rogers. If it weren’t for one ERA-inflating start (eight earned runs in three innings vs. the Phillies on Sept. 11), he’d be getting more 2021 buzz.
— Matt Kelly
Spencer Howard — RHP, Phillies
Key number: .217 BA allowed / 41% whiff rate on sliders
Though Howard may not have fully lived up to expectations as the Phillies’ top prospect during his 2020 debut, the 24-year-old right-hander certainly showed flashes of his potential. Along with packing a fastball that sat at 94 mph and touched 97 mph last season, Howard also has a devastating slider, against which opponents hit just .217 while whiffing on 40.7% of their swings. In fact, per Statcast, two of the pitchers most similar to Howard based on velocity and movement profile are reigning NL Cy Young Award winner Trevor Bauer and White Sox ace Lucas Giolito.
With the Phils easing Howard into the rotation last season, he completed five innings in just one of his six outings and threw fewer than 70 pitches four times. Assuming Howard has a normal buildup in Spring Training this season, he should begin the year in the rotation and be given the opportunity to stretch out to a typical workload. But even in that limited action last season, Howard managed to turn some heads in the NL East. Freddie Freeman, the 2020 NL MVP, noted that Howard has “really good stuff” following the rookie’s big league debut.
Howard will need to work on disguising his changeup (.429 batting average allowed) and mixing in his curveball a bit more (thrown only 6% of the time in ’20), but MLB’s No. 42 prospect certainly has the tools to take the next step.
— Paul Casella
Zach Eflin — RHP, Phillies
Key number: 22% gap between strikeout and walk rate
Overshadowed by Aaron Nola and Zack Wheeler (and perhaps even Howard, the top prospect on the same team, chosen just ahead of him here), Eflin also might be dismissed for a 4.63 ERA and 7.3 K/9 in his five-year career. Those underwhelming numbers make some think he’s settled into a role as a back-of-the-rotation arm without upside. But take a closer look at his improved bat-missing ability in the shortened 2020 season, when he struck out 70 in 59 frames (28.6% K rate) while posting a typically solid walk rate (6.1%). That comes to an impressive 22.4% K-BB mark, which ranked in the top 15 among pitchers to throw at least 50 innings last year — in line with Max Scherzer, Luis Castillo and Blake Snell. Good company for Eflin, who still could take another step, considering the 6-foot-6 righty is only entering his age-27 campaign.
Also promising? Eflin transitioned from throwing his hittable four-seam fastball to relying much more on his sinker in ’20. The pitch registered a .296 expected wOBA last year (.290 in ’19), compared to a .333 xwOBA (.335 in ’19) on his four-seamer. The sinker’s success helped Eflin post an expected ERA of 3.31 — good for a top-25 mark among pitchers with 200 batters faced — and a career-best 3.97 ERA. If his adjusted repertoire leads to more weak contact and continued swings-and-misses, he’s poised to give Philly a reliable 1-2-3 punch atop its rotation.
— Jason Catania
Kyle Wright — RHP, Braves
Key number: 1.80 ERA over final 3 regular-season starts + NLDS Game 3
Wright was one of Atlanta’s most heralded pitching prospects, and that’s saying something considering the Braves also have Max Fried and Mike Soroka in the rotation. But unlike those two, Wright hasn’t yet enjoyed sustained success at the MLB level. Entering the abbreviated 2020 season, Wright needed to get right in a hurry and show the Braves he had what they saw in him when they drafted him fifth overall in 2017. Now, heading into ’21, there are reasons to expect a breakout campaign.
Wright got off to a rocky start last season — he was optioned to the Braves’ alternate training site when his ERA through four starts stood at 7.20. But fast-forward to Game 3 of the NLDS against the Marlins, and he was tossing six scoreless innings in a 7-0 Atlanta victory to clinch a spot in the NLCS. That was Wright’s fourth straight strong start — he finished the regular season with a 2.37 ERA over his final three outings. He said after the NLDS victory that getting sent to the alternate training site was really helpful, because he made some important changes there. If we see more of what we saw last September and October, Wright could have a huge 2021.
— Manny Randhawa
Adrian Morejon — LHP, Padres
Key number: 96.6 mph avg. fastball velo, 57% whiff rate on knuckle-change
This one’s kind of a gut call, since the Padres’ super-rotation and bullpen are so deep right now that the 21-year-old lefty Morejon might not even have a roster spot right away. But here’s the bold prediction: Come October, this kid is either going to be a starter in San Diego’s playoff rotation, or its postseason closer. His stuff is that overpowering.
With an explosive upper-90s fastball, wipeout “knuckle-change” and a pair of swing-and-miss breaking balls, Morejon is going to pitch himself onto the team at some point and never look back. Pay a lot more attention to the arsenal that produced an 11.6 K/9 in 2020 (compared to just 1.9 BB/9) than the 4.66 ERA.