10 MLB Pitching Prospects Showing Better Stuff In 2024
Image credit: Cardinals LHP Quinn Mathews (Photo by Tom DiPace)
After two or three starts in April, there typically isn’t enough new information that will significantly alter our long-term forecast for a pitcher.
One thing that can quickly stick out enough to make us adjust our projection for a player is a material, measurable jump in stuff. The same isn’t necessarily true in reverse—a pitcher who doesn’t look as crisp as usual pitching in cold weather in April deserves some leniency—but if a pitcher comes out showing a skill he’s never had before, sometimes the needle can move quickly.
The easiest change to measure is increased velocity, but it could be a new pitch that a player has taken to quickly or some other adjustment that has produced more effective movement on a pitch, be it a fastball or an offspeed weapon.
These are 10 pitching prospects who we have already seen take a leap forward with their stuff this year. The list includes multiple pitchers who are throwing 4-5 mph harder this year, a mix of some famous names and deeper sleepers to watch in the lower levels.
1. Brett Wichrowski, RHP, Brewers
Wichrowski is one of the biggest arrow-up pitching prospects in baseball. Every team had several opportunities to add him last year, but the Brewers snapped him up in the 13th round of the draft and signed him for $100,000. At the time, Wichrowski was a junior at Bryant, where he had a 4.50 ERA split between starting and the bullpen, with a 64-25 K-BB mark in 50 innings and a fastball that was sitting in the low 90s, topping at 96 mph.
As Josh Norris pointed out, his stuff exploded as soon as he got to spring training, where he touched 100 mph. He has since reached 101 mph, sitting at 94-97 mph as a starter for High-A Wisconsin, where he has a 1.64 ERA with 14 strikeouts and two walks in 11 innings. The extra five mph to give him a triple-digits fastball is exciting, but it’s a mid-80s slider that breaks like a Whiffle ball at times that helps him pile up empty swings. Wichrowski has transformed himself from a player outside the Brewers Top 30 prospects entering the year into one whose pushing his way toward the top 10 prospects in one of the game’s strongest farm systems.
2. Bishop Letson, RHP Brewers
With Wichrowski and Letson, the Brewers have two of the pitchers whose stuff has made the biggest leap forward of anyone in the minors, with both acquired after the 10th round in the draft last year. Letson was a gangly Indiana high school pitcher who was not heavily recruited before he committed to Purdue. Coming into the 2023 draft, Letson wasn’t overpowering—his fastball topped at 93 mph—but at 6-foot-4, 170 pounds with a loose arm, fast arm speed and good athleticism, he hit a lot of projection checkpoints that pointed to future velocity gains.
Less than a year after the Brewers drafted him in the 11th round and signed him for $486,200, that projection has started to materialize. Pitching for Low-A Carolina, Letson now sits at 92-95 mph and has reached 98. His slider flashes above-average potential and he has shown feel for a changeup as well. Through two starts the Brewers have kept Letson’s workload tight at just 5.2 innings, with Letson allowing just one hit and striking out eight, though he has walked five. The early signals point to an arm who could be one of the bigger risers among lower-level pitching prospects.
3. Quinn Mathews, LHP, Cardinals
Mathews pitched four years at Stanford before the Cardinals drafted him in the fourth round last year. Mathews’ best pitch was his changeup, which he used to keep hitters off a fastball that sat in the low 90s and touched 94 mph. He had an unusual amount of physical projection remaining for a college pitcher at 6-foot-5, 188 pounds, and now his fastball has spiked in pro ball.
This year Mathews has been up to 97 mph, cruising at 93-96 mph with good riding life. Through 12 innings in Low-A Palm Beach, Mathews has an ERA of 0.75 and he has struck out 25 of the 50 batters he’s faced (50%), though he has issued nine walks. As a 23-year-old in Low-A, Mathews should be too good for this level, but the extra zip on his fastball to pair with what was already an impressive changeup makes for a much more intriguing lefty profile.
4. Michael Forret, RHP, Orioles
Forret was a 14th-round pick from State JC of Florida last year who signed with the Orioles for $450,000. He pitched in the low 90s, touched 94 mph and showed the strength projection in his 6-foot-3, 190-pound frame to think there could be more in the tank. The 20-year-old righthander has added a few ticks to his fastball already this year in Low-A Delmarva, sitting 93-95 mph and touching 97. His plus slider has been a major weapon in the low-to-mid 80s, giving him a sharp breaking ball that snaps off with late bite to miss bats. Overall, Forret has a 3.46 ERA with 19 strikeouts and three walks in 13 innings, making him one of the more intriguing sleeper prospects in the lower levels.
5. Jonah Tong, RHP, Mets
A Canadian who went to Georgia Premier Academy when the Mets drafted him in the seventh round in 2022, Tong had a difficult adjustment to pro ball. Between the Rookie-level Florida Complex League and Low-A St. Lucie last year, Tong had a 6.00 ERA and had more walks (22) than innings (21). It’s been a totally different story this year in the 20-year-old Tong’s return to Low-A, where he has yet to allow an earned run in 12.2 innings and owns a sparkling 27-5 K-BB mark.
The reduction in walks is a welcome sign, but even better is that he’s doing it with an uptick in stuff. Tong last year would sit in the low 90s and touch 93 mph, but this year he’s pitching at 91-94 mph and has touched 97. It’s a fastball that averages 20 inches of induced vertical break from his high arm slot and gets a lot of swing-and-miss when he elevates. Tong throws a big-breaking overhand curveball with good depth and a mid-80s slider and a mid-80s changeup that’s behind his breaking stuff. There’s some effort to the operation and a chance he ends up in the bullpen, but Tong has made himself into a much more intriguing sleeper compared to what he showed a year ago.
6. Adam Serwinowski, LHP, Reds
Serwinowski’s change in stuff has been more subtle relative to some of the other pitchers on this list, but it’s still a notable difference. Serwinowski, 19, is a 6-foot-5 lefty who has thrown 12 scoreless innings with a 15-3 K-BB mark for Low-A Daytona. His fastball sits at 93-95 mph, reaches 97 and can get on hitters quickly because of the way he hides the ball behind his body in his delivery. The velocity has been the same as last year, but this year Serwinowski is getting an extra 3-4 inches of carry on his fastball, which has created an abundance of hitters whiffing underneath the ball when he elevates. Serwinowski’s fastball already played well at the top of the zone, so maybe this doesn’t even matter, but the extra movement could play to his strength and accentuate an already difficult pitch for hitters to square up.
7. Santiago Suarez, RHP, Rays
Suarez was an already talented prospect coming into the year who has continued to trend up. His track record of filling the strike zone has continued through three starts with Low-A Charleston, where the 19-year-old has a 19-1 K-BB mark in 16 innings and a 1.13 ERA. It’s a simple, repeatable delivery and his fastball has inched ahead this year to where it’s now sitting in the mid-90s and reaching 97 mph. With the way he’s pitching, he could find himself in Top 100 conversations later this season.
8. Chase Petty, RHP, Reds
The 2024 Chase Petty looks more like the version of Chase Petty that many scouts had projected going into the 2021 draft compared to what he has looked like the past two years. In high school, Petty touched triple digits with his fastball and flashed a plus slider, though with effort to his delivery and erratic fastball control. In pro ball, however, Petty has been a strike-thrower who has moved quickly, reaching Double-A at the end of 2023 as a 20-year-old. The pitchability was better than expected, but he was often sitting in the low 90s, occasionally scraping a 96.
This spring, Petty’s velocity is up. He’s now sitting 94-98 mph and flashing 100 mph heat. So is Petty a better prospect now? His velocity is up, but he’s allowed at least a run per inning in each of his first three starts, with an 11.45 ERA in 11 innings, 12 strikeouts and seven walks. Whether Petty can keep pitching with the power he has on his fastball now while maintaining the touch and feel he showed last year is something to watch.
9. Zebby Matthews, RHP, Twins
An eighth-round pick out of Western Carolina in 2022, Matthews entered the year as the No. 14 prospect in the Twins system. Matthews showed outstanding control in his first full season in 2023, issuing just 15 walks in 105.1 innings (1.3 BB/9) split between Low-A Fort Myers and High-A Cedar Rapids. Back at Cedar Rapids this year, the 23-year-old righthander is again filling the zone, with no walks and 12 strikeouts in 10 innings to go with a 2.70 ERA. More noteworthy is a bump with his fastball. The 6-foot-5, 225-pound righthander is averaging close to 2 mph more on his fastball this year, sitting at 94-97 mph and reaching 98. There’s no plus pitch among Matthews’ secondary stuff, but the extra gear on his fastball adds a little power to the control artist’s attack.
10. Moises Chace, RHP, Orioles
Chace’s stuff across the board is getting more swing-and-miss than it did a year ago. A 20-year-old righthander with High-A Abderdeen, Chace is throwing slightly harder than he did in 2023, sitting at 93-95 mph and reaching 96 mph with a riding fastball. He’s getting a high amount of whiffs both with a changeup that has good fade and separation off his fastball as well as a high-spin slider (2,700-2,900 rpm) that has sharp sweep across the zone. It’s a starter’s repertoire, though after recording a 15-to-2 strikeout-to-walk ratio in his first two starts, Chace walked six in four innings in his last outing. Control has been an issue for Chace before—he walked 53 in 68 innings last year—so while he has the stuff to start, location will be key for him to stick in that role.
