10 Breakout MLB Pitching Prospects So Far In 2024
Image credit: (Photo by George Kubas/Diamond Images via Getty Images)
No species of prospect is more eruptive from season to season than starting pitchers. Success is fleeting for many highly-ranked arms. Others with lesser pedigree often perform to less fanfare. That’s the nature of the minor leagues, and a certain level of anonymity lingers until prospects are ranked and move to the verge of the majors.
There’s a strong case that highly-ranked top-of-the-draft arms have the most success. Since 2022, the three most valuable MLB starters according to fWAR are Kevin Gausman, Zack Wheeler and Aaron Nola. All three are former top-10 picks.
However, plenty of names in the top 20 were not first-rounders. Extended even more, there’s plenty of players with lesser pedigree who provide valuable innings in the middle and back of rotations.
Today, we’ll examine lower-pedigree performers showing signs of potential breakouts in 2024. To do so, I culled a group using the following methodology:
- Age 25 or younger
- Qualified for ERA title
- Swinging strike above 13%
- .250 opponent batting average or below
- 26%+ K rate
- 3.60 or lower xFIP
I also omitted some of the more well-known performers this year, such as Chase Dollander, Tink Hence, Zebby Matthews and Quinn Mathews. All are well-known arms and Top 100 Prospects.
Here are 10 pitching prospects from that group who caught my attention.
Matt Wilkinson, LHP, Guardians
Is Wilkinson really underrated or undervalued considering he is already a social media sensation in a small corner of the baseball world? ‘Tugboat’ put up video game numbers while taking the Carolina League by storm over his first eight starts of the season. He struck out 48% of batters faced while walking just 6.1% en route to a stellar 1.12 ERA and 1.53 xFIP. Cleveland promoted Wilkinson to High-A Lake County in late May and he has performed well in four starts.
To date, Wilkinson’s 1.78 xFIP leads all non-complex league qualified pitchers this season. His profile is unusual. Wilkinson mixes three pitches in a four-seam fastball, sweepy slider and a changeup. His fastball sits 89-90 mph with lots of armside run from a very low release height due to his low three-quarters slot and above-average extension. Wilkinson uses his slider most frequently. It’s a 78-79 mph sweeper with around 10-12 inches of horizontal break. His changeup is a good chase pitch, although he struggles to command it.
All of Wilkinson’s pitches generate swinging strikes at rates of 18% or higher and his release heights are fairly tight, lending credence to the idea he has deceptive tunneling traits. His lack of premium stuff makes him a tough read.
Sean Sullivan, LHP, Rockies
A draft-eligible sophomore, Sullivan signed for $1.7 million out of Wake Forest last summer. He has been one of the top pitchers in High-A this season. Sullivan has 76 strikeouts compared to just six walks over 68.1 innings and 11 starts, owning a 2.50 ERA and 0.88 WHIP.
The idea of Rockies pitching prospects probably scares many. But Colorado is having some real success with high-profile college arms. Chase Dollander, Carson Palmquist and Michael Prosecky are other recent success stories. Sullivan falls into the category of soft-tossing lefthander with deceptive release traits.
His fastball sits just 87-88 mph, but he gets over seven feet of extension with above-average vertical break for his release and sidearm slot. Sullivan throws his heater nearly 70% of the time. His uses his changeup 20% of the time and his slider a little above 9%. That’s dominant fastball usage, and it makes sense considering it’s such a unique pitch. Sullivan finds success despite lack of traditional stuff due to deception, shape and fastball plane. Whether he can keep this up on his way to the majors is a fair question, but he has been dominant so far this season.
Braxton Ashcraft, RHP, Pirates
Pirates pitching development can pat itself on the back following the success of Jared Jones. Add in ready-made ace Paul Skenes, and the Pirates have the top-of-the-rotation bedrocks necessary for success. Jones and Skenes may not be the only rookie pitchers contributing in Pittsburgh this summer, either. Ashcraft is enjoying a breakout season with Double-A Altoona and Triple-A Indianapolis.
Over 13 appearances, 12 starts, Ashcraft has 3.23 ERA, 1.06 WHIP, with 71 strikeouts to 11 walks across 64 innings. He has shown the ability to get deeper into starts this season with eight appearances of five or more innings, including five starts of six or more innings. Health and efficiency were concerns for Ashcraft in the past, but he’s showing far more refinement in 2024.
No one questions Ashcraft’s stuff. He sits 95-96 mph touching 98 mph at peak with pedestrian shape but lots of strikes. He mixes two breaking balls as secondaries in a low-to-mid-80s power curveball with two-plane break and an upper-80s cut-slider. Ashcraft shows average or better command of both of secondaries and misses bats while limiting hard contact with each.
The 24-year-old is on the 40-man roster, in Triple-A and just a shout away from making his big league debut.
Santiago Suarez, RHP, Rays
Signed by the Marlins out of Venezuela in 2022, the Rays scooped Suarez up in the Xavier Edwards trade with Miami. Over the first half of 2024, Suarez looks like a potential breakout with production and the stuff to match.
While Suarez’s 4.42 ERA is mediocre, his underlying ERA estimators are excellent. He has a 2.59 xFIP and a 28.6% strikeout rate compared to a 1.9% walk rate. Suarez sits 94-95 mph with above-average ride and good fastball plane allowing his fastball to miss an above-average rate of bats (14% swinging strike rate). Suarez shows a trio of secondaries with potential to be average or better. His primary secondary is his upper-80s cutter that generates whiffs and bad contact with lots of strikes. Suarez’s curveball sits 80-81 mph with slurvy shape. His split-changeup sits low 90s. Suarez has shown a promising combination of stuff and strikes in 2024.
Gary Gill Hill, RHP, Rays
Not too long ago, Gill Hill was a highly projectable but raw high school player from New York. He popped late in the draft process, switching his commitment from Fairleigh Dickinson to Wake Forest. Neither school landed Gill Hill because he instead signed for $597,500 in the sixth round of the 2022 draft. After a late-season cup of coffee with Low-A Charleston to end 2023, Gill Hill returned in 2024. Over 12 starts with the River Dogs, Gill Hill is sporting a 2.11 ERA supported by a 2.95 xFIP with 62 strikeouts to 14 walks across 59.2 innings.
Gill Hill misses bats, but his elite groundball rate really separates him from other breakout pitchers. Gill Hill has a 59.2% groundball rate in 2024 on the strength of his 93-95 mph sinker. He uses the pitch nearly 60% of the time while mixing in a quartet of secondaries in a mid-80s gyro slider, a low-80s two-plane curveball, a mid-80s changeup and an upper-80s cutter. It’s a deep pitch mix with a good mix of whiffs and strikes. Still loose and projectable, Gill Hill has potential to show more ceiling in the coming years.
Jean Cabrera, RHP, Phillies
Cabrera showed signs of breakout potential dating back to spring training. He flashed impressive sections during his Spring Breakout outing and had some buzz coming out of camp. Over a dozen starts with High-A Jersey Shore, Cabrera has been phenomenal, pitching to a 3.22 ERA, supported by a 3.48 xFIP with a 28.3% strikeout rate and a 7.7% walk rate.
Cabrera gets a high rate of groundballs in addition to showing swing-and-miss stuff and command. His arsenal mixes fastball, slider and changeup and he uses his secondaries more than 50% of the time. Cabrera throws his 94-95 mph fastball just 42% of the time. It has dead-zone shape, and while he’s adept at getting it in the zone, it misses very few bats (17.3% miss rate). Batters have hit the pitch hard to the tune of a .412 wOBA.
Cabrera’s secondaries are strong and they do a heavy amount of the lifting. He uses his slider 33% of the time and throws his changeup 25% of the time. His cambio is his most-thrown pitch against lefthanded hitters. Cabrera has power on his fastball, but rides the quality of his sweepy low-80s slider and hard-running mid-to-high-80s changeup.
Samuel Aldegheri, LHP, Phillies
The Verona, Italy native is another breakout prospect in the Phillies’ ever-growing stable of intriguing pitching prospects. Injuries have plagued Aledegheri since he signed in 2019, but he has been healthy in 2024.
Over 11 starts with High-A Jersey Shore, Aldegheri owns a 2.75 ERA supported by a 3.26 xFIP. He strikes out 35.5% of batters compared a 10.3% walk rate. Aldegheri mixes four pitches from a tight release cluster. His fastball sits 92-93 mph with above-average ride (18.5 inches of IVB) with slight cut. Aldegheri pairs his fastball with a trio of secondaries led by a mid-80s gyro slider that grades out as his best pitch, a mid-70s two-plane breaking curveball and a low-to-mid-80s changeup that’s generated a 53% whiff rate to date.
Aldegheri is showing starter traits with a solid mix, deception and the ability to work and handle five or more innings consistently.
Fernando Perez, RHP, Blue Jays
One of the standouts of Baseball America’s spring training looks, Perez is one of the few healthy and performing pitchers in the Blue Jays system at the moment. Perez won’t wow you with stuff. Instead, he lulls opposing lineups to sleep with consistent execution and a potentially plus changeup.
Perez has made a dozen starts pitching to a 3.74 ERA with an even better xFIP at 3.30. Perez has some swing-and-miss abilities but it’s his above-average command that drives his profile with a 7.2% walk rate and a 19.6% K-BB%. The only two qualified pitchers aged 20 or younger with a better K-BB% than Perez are Santiago Suarez and Gary Gill-Hill (both discussed above). Perez’s four pitch mix isn’t extraordinary, but he mixes his four-seam fastball, slider and changeup effectively. Perez sits 92-93 mph with pedestrian shape on his fastball mixing a mid-80s gyro slider, his signature low-80s changeup and he’ll flash an upper-70s curveball from time to time as well.
Carson Palmquist, LHP, Rockies
Much like the aforementioned Sean Sullivan, Palmquist was drafted as a soft-tossing lefthander with unusual release traits. By no means has Palmquist added significant power in 2024. He is, however, sitting closer to 92 mph than 91 mph and his slider and changeup are being thrown slightly harder as well.
Palmquist has added some run to his changeup and some sweep to his fastball. The combination of those improvements has led to strong results in the first half of 2024. Over 12 starts with Double-A Hartford, Palmquist owns a 2.97 ERA, with a 3.68 xFIP while striking out 33% of batters he faced. Palmquist sits in the top 10 of almost all statistical categories at the moment in the Eastern League. He looks poised for a promotion any day now.
His unique mix is driven by his sidearm slot and sub-five-foot release height. As has been discussed many times now, this low release height creates an unusual plane on his fastball making his perceived velocity nearly a mile per hour faster. It also makes it more difficult for hitters to barrel. Palmquist’s slider misses bats at an above-average rate with a 17.3% swinging strike rate on the season. Palmquist will show his changeup and it will miss bats when used situationally, but has been hit hard in 2024. It’s another funky lefty profile with good stuff even if it’s nontraditional.
Winston Santos, RHP, Rangers
Signed out of the Dominican Republic in July of 2019, Santos had a strong 2022 campaign. His 2023 season was sometimes disastrous, though, and pitched to a somewhat undeserved 6.29 ERA with High-A Hickory. Santos returned to the level in 2024 and has looked electric at times matching stuff and strike-throwing.
Santos over a dozen starts in 2024 has pitched to a 2.80 ERA with a 3.41 xFIP. He is striking out 30.5% of batters versus a 7.5% walk rate. Santos’ stuff has taken a major jump year-over-year. Both Santos and Rangers player development deserve credit for cleaning up his four-seam fastball tilt from 1:39 in 2023 to 1:00 in 2024. The cleaner spin axis allows his fastball to ride and run with traits more consistent of a four-seam fastball. On the season Santos is sitting 95-96 mph with now 17-to-18 inches of induced vertical break on average with 9-10 inches of armside run.
Beyond the fastball, Santos’ slider has added power now sitting 84-85 mph–up 2 mph from 2023 with cleaner gyro shape. Santos’ changeup has improved as well, moving a mph harder with a little more armside run and better vertical separation off his fastball compared to 2023. The overall changes have put Santos in the conversation for best-performing pitching prospects in the Rangers system in 2024.
