Breakout MLB Pitching Prospects Who Gained Fastball Velocity In 2023


Image credit: Jack Perkins (Photo by Eddie Kelly / ProLook Photos)

Velocity has become so synonymous with the modern game it’s become cliche to even mention its importance. Each year pitchers head into the offseason looking to improve in a variety of areas. For many pitching prospects, adding velocity is a key focus of their offseason.

With a full season worth of samples to work with, we compared each prospect’s 2022 velocity to their 2023 velocity. In the interest of comparing likes to likes, we looked at pitchers with at least a 100 fastball sample on each of the last two seasons and removed any pitchers who didn’t pitch at a full season level each of the last two seasons. There are assumed velocity gains for teenagers on the complex and would account for a large majority of velocity gainers. 

Year-Over-Year Four-Seam Velocity Gainers 

Player23 Level23 ORG2022 FF Velo2023 FF VeloVelocity +/-
Jack PerkinsDouble-AOAK9094.74.7
John McMillonDouble-AKC93.297.74.5
Yerlin RodriguezLow-AMIL92.196.54.4
Tyler BaumDouble-AOAK90.7954.3
Fraser EllardDouble-ACWS91.395.54.2
Valentin LinarezDouble-APIT90.594.54
Randy BerigueteLow-ABAL92.195.63.5
Ruben GalindoLow-ASD91.5953.5
Alec GamboaTriple-ALAD91.194.53.4
Michael ByrneDouble-ACIN90.193.43.3
Kevin GowdyDouble-ALAD9396.33.3
Listher SosaDouble-AAZ91.794.93.2
Ernesto JaquezHigh-ACWS92.195.23.1
Easton LucasTriple-AOAK90.993.93
Mike ParedesHigh-AMIN90.193.13
Stevie EmanuelsDouble-AOAK91.994.93
Walker BrockhouseHigh-AHOU91.794.73
Adrian HernandezDouble-ATOR90.393.22.9
Dylan HeidDouble-ABAL90.1932.9
Jairo IriarteDouble-ASD92.595.42.9
Tobias MyersTriple-AMIL90.593.42.9
Carlo ReyesDouble-ALAD90.693.42.8
Connor CookeTriple-ATOR92.695.42.8
Dominic PipkinDouble-APHI93.2962.8
Cole RagansTriple-AKC92.895.52.7

The above group includes every pitcher who threw at least 100 fastballs in each of the last two seasons and made at least one appearance at a full-season level over the last two seasons. 

When looking at the group above, there are some trends that become clear. 

First, the majority of these velocity gainers are relievers. In fact, 21 of the 25 pitchers on this list are primarily relievers, while all 25 pitchers on this list made at least one relief appearance. Moving to shorter stints and ramping up velocity go hand in hand, as pitchers air it out more in relief roles. 

Several of the pitchers on this list are converted starters moved to the bullpen in 2023. Among those names are the Twins’ Mike Paredes, the Athletics’ Stevie Emanuels, the Pirates’ Valentin Linarez and the Phillies’ Dominic Pipkin

The only true starters on this list are the Athletics’ Jack Perkins (who happens to be the biggest gainer overall on the list), the Padres’ Jairo Iriarte, the Royals’ Cole Ragans and the Brewers’ Tobias Myers. Ragans was arguably the biggest breakout pitcher in the major leagues this season, while Iriarte was one of the biggest breakout pitching prospects of 2023. Myers’ claim to fame is being the player the Rays traded for Junior Caminero, but has struggled to recapture his 2021 form. Perkins is the most underappreciated gainer of the group. A fifth-round pick in 2022 out of Indiana, Perkins spent three seasons at Louisville as a reliever before making the jump to the rotation after transferring to Indiana. Huge jumps in stuff and execution from college relievers isn’t terribly uncommon. 

Among the relievers on this list are some of the top names in the minor leagues. Connor Cooke was a revelation for the Blue Jays this summer, as he pitched his way to Triple-A by season’s end with a robust three-pitch mix. Dominic Pipkin was a former high school pick the Phillies converted to a reliever this season, who jumped multiple levels this year. Easton Lucas saw a significant velocity jump this season with the Orioles and was traded to the Athletics in the Shintaro Fujinami trade. 

Former Phillies second rounder Kevin Gowdy and Carlo Reyes fall into the category of Dodgers reclamation projects. But Gowdy, who was a part of the Phillies’ 2015 draft, never got out of the starting blocks in 2023.

Finally, this is a reminder that not all velocity gains lead to success, as several pitchers on this list indeed experienced down years. 

Year-Over-Year Two-Seam Fastball Gainers

Player2023 Level23 ORG2022 Velocity2023 VelocityVelocity +/-
John RooneyAAALAD88.892.94.1
Joelvis Del RosarioDouble-AOAK89.392.93.6
Michael ByrneDouble-ACIN90.193.73.6
Stephen KolekTriple-ASEA91.594.63.1
Jedixson PaezLow-ABOS87.690.42.8
Brett de GeusTriple-AKC92.595.32.8
Garrett StallingsTriple-ABAL89.992.72.8
Brett LockwoodLow-ACIN8688.72.7
Bryan HoeingTriple-AMIA91.3942.7
Nick FrazeDouble-ATOR89.191.72.6
Eduardo SalazarTriple-ACIN91.293.82.6
Franco AlemanDouble-ACLE92.795.32.6

Not all pitchers throw four-seam fastballs. Above are the top gainers among two-seam and sinking fastballs. Multiple Reds’ pitchers crack this list in Michael Byrne, Brett Lockwood and Eduardo Salazar. Lockwood gets negative vertical break on his sinker but has below-average velocity even after the 2023 gains. This was also Lockwood’s third season in Low-A.

John Rooney is another example of the work the Dodgers’ player development staff does, as he gained a significant amount of velocity in 2023. The Mariners’ Stephen Kolek, the Royals’ Brett De Gaus and the Marlins’ Bryan Hoeing all pushed their average two-seam velocity above 94 mph in 2023.

Top 100 Pitchers 

Player23 Level23 ORG2022 FF Velo2023 FF VeloVelocity +/-
Jairo IriarteDouble-ASD92.595.42.9
Jackson JobeDouble-ADET94.196.52.4
AJ Smith-ShawverTriple-AATL94.595.30.8
Jared JonesTriple-APIT95.696.30.7
Kyle HarrisonTriple-ASF93.494.10.7
Ricky TiedemannDouble-ATOR94.4950.6
Mick AbelDouble-APHI95.695.90.3
Connor PhillipsTriple-ACIN9696.20.2
Tink HenceDouble-ASTL95.595.60.1
Robert GasserTriple-AMIL92.392.30
Gavin StoneTriple-ALAD94.594.1-0.4
Owen WhiteTriple-ATEX94.993.2-1.7
Mason MillerTriple-AOAK100.798.9-1.8

Listed above are the pitchers on our current Top 100 list that pitched in each of the last two seasons. With countless injuries to top pitching prospects in recent seasons, this group is fairly thin. Among the 13 pitchers in this sample are only two: Jairo Iriarte (previously discussed among the minor leagues greatest gainers) and Tigers prospect Jackson Jobe. The latter dealt with injuries during his 2022 campaign and found his premium form in 2023.

There’s a group of slight gainers in the Braves’ AJ Smith-Shawver, the Pirates’ Jared Jones, the Giants’ Kyle Harrison and the Blue Jays’ Ricky Tiedemann. Harrison and Tiedemann both were used in shorter stints this season, which could explain some of the gains. Both Jones and Smith-Shawver experienced breakout seasons that saw their prospect stock climb significantly since January. 

Mason Miller is the biggest velocity loser among this group, but much of that is the product of a small 2022 sample size. Miller was one of the top, if not the top, breakout pitching prospects of 2023, as he dominated in a short stint in the major leagues early in the season before missing several months with forearm tightness. 

The truly concerning loss of velocity within this group is Owen White. The Rangers’ righthander saw a nearly 2 mph dip in his average four-seam velocity this season in a nearly identical sample size. White lost vertical break on his fastball as well year-over-year, and his whiff rate against the pitch plummeted from 33% in 2022 to just 17.1% in 2023. 

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