Spring training is back and we’re just a month away from meaningful baseball. There’s a saying that spring training is for pitchers since they’re the first to report to training camp, their workloads are closely monitored, and the objective is to get their arms built up toward game shape by the end of March.
Throughout their quest to get warm for the season, a wide variety of data points are tracked by their teams and fans alike in both bullpen sessions and live game action, such as velocity, pitch shape, and pitch mixes just to name a few. The latter is especially important for any pitchers who decided to make changes to their arsenal over the winter, a group that seems to be growing by the day.
What some fans may not know is that Statcast data is available in some divisions of the minor leagues. I scraped every pitch of the 2024 Triple-A season in Python using this tutorial from Robert Frey and recently identified five hitting prospects to watch in spring training based on their Statcast metrics. Now, it’s time to highlight the pitchers. Here are five young arms that are worth keeping an eye on over the next few weeks thanks in part to their minor league data from 2024. Once again, overreact accordingly!
1. Jacob Misiorowski, RHP (MIL)
Key Stat: 98 mph average fastball velocity
He isn’t a prospect that generates a ton of headlines, but in many ways, Misiorowski is a pitching coach’s dream. His four-seam fastball looks like it was engineered in a lab, and facing it is not a comfortable challenge for opposing hitters. He spent most of the season as a starter at Double-A Biloxi but he got his chance at Triple-A during the second half in a relief role, and once he got there, his heater averaged 98 mph.
What really makes him an outlier, though, is his extension down the mound during his delivery – seven feet and a tad under five inches, to be exact – which makes that 98 mph look more like 100 flat. Now, combine that with a very low vertical release point and over 2,500 RPM in spin. These ingredients are what elevate this from simply being a hard fastball to one that some MLB GMs think is the very best one in the minors. I’d also be remiss not to mention that Misiorowski is 6’7″ and 190 pounds, which adds a great deal of deception to the shape of this fastball when considering the low release point even when hitters are sitting on it. If you’re reading these numbers and picturing an alien-looking pitch that makes you question how anyone’s supposed to hit it, you aren’t that far off. Here’s a video of Misiorowski’s fastball from the All-Star Futures Game in 2023. I could watch this sort of thing all day.
That fastball helped his transition from Double-A to Triple-A and from the rotation to the bullpen a smooth one. Misiorowski recorded a 2.55 ERA, 0.85 WHIP, and 22 strikeouts in 17.2 innings following his promotion to Triple-A Nashville. The Brewers have a very advanced pitching development system, and if they can keep churning out arms like this that don’t come with much fanfare but end up becoming key contributors on their staff, then they’re going to keep winning a lot more games than everyone expects despite initially appearing to get worse on paper. Misiorowski isn’t automatically set to enter a high-leverage role in their bullpen as Trevor Megill, Abner Uribe, and Joel Payamps will all be back to lead one of the more formidable relief groups in the league. However, if he gets some runway in the majors this year, don’t be surprised if he bursts onto the scene with authority.
2. Logan Henderson, RHP (MIL)
Key Stat: 33.3% Chase%
Believe me, I wish I could spread the love a little more, but once again, the Brewers’ pitching lab is making it difficult to do so. Logan Henderson is a true under-the-radar prospect. He was drafted in the fourth round in 2021 and then underwent Tommy John surgery shortly thereafter, so he had to hang around the lower levels of the minors for a couple of years. 2024 saw him steadily climb up the ranks to Triple-A and he struggled a bit once he got there (4.56 ERA, 5.13 FIP), but digging deeper into the metrics makes it obvious that those results don’t tell the whole story.
What caught my eye was how frequently Henderson was getting batters to swing at pitches outside the strike zone and in the shadow zone in his age-22 season. The sample size was small as he only threw 23.2 innings at Triple-A last year, but he led all 22-and-under pitchers in both Chase% and Shadow Swing%. Interestingly, second behind Henderson on the Chase% leaderboard was Bubba Chandler, a consensus top-50 prospect for the Pirates. As well, despite barely accumulating groundballs compared to his peers, he managed to keep barrels and dangerous contact in the air to a minimum.
Henderson doesn’t have the demonic stuff that a lot of today’s top young arms feature, but he has still maintained a rate greater than one strikeout per inning at every level of the minors to this point. He’s a fastball/changeup guy who mixed in the occasional cutter at Triple-A, and the changeup received a 60 grade from Fangraphs in their 2025 preseason report. As far as changeups go, it’s pretty unorthodox and doesn’t have the traditional low spin rate or vertical drop, relying instead on a whopping 17.8 inches of horizontal break from a straighter, over-the-shoulder release point to be effective.
As it stands, there isn’t a path for Henderson to break into the Brewers’ rotation in 2025 barring injury. However, he has the makings of becoming yet another example of how the Brewers have kept winning up until now – maximizing homegrown development instead of pursuing free agents or making big trades in which they assume the role of the traditional “buyer”. If he can find another gear at Triple-A, he’s a candidate to get some big-league reps in the second half of the season. It’s not easy to induce this much aggression from hitters in Triple-A at Henderson’s age, and it’ll be exciting to see how he can build on that this year.
3. Andrew Walters, RHP (CLE)
Key Stat: 24.1% Heart Zone SwStr%
Continuing on with the theme of trying to identify surprise contributors on the mound before they break out because they have good underlying metrics and play for teams with established pitching labs, I’m going to make a prediction here: Andrew Walters will be getting high-leverage innings during Cleveland’s stretch run/playoff push this year. He has less than 10 innings of MLB experience to his name and is projected by Fangraphs’ depth charts to pitch the eighth-most innings in the Guardians bullpen, which would make him one of the final additions to the big-league roster. The bullpen in question also features workhorses Cade Smith, Hunter Gaddis, and Tim Herrin ahead of Emmanuel Clase, and new veteran additions Paul Sewald and Jakob Junis. There is also the new trade acquisition Slade Cecconi who came over in a deal that sent one of their best hitters the other way. So, why do I feel so confident in Walters’ role with the big club?
It can’t be boiled down to just one thing, but it starts with that big, red 100th-percentile marker on the player card above. Walters led all Triple-A pitchers under 25 with at least 100 BBE on the season in swinging strike rate on pitches down the heart of the plate. The fact that his stuff played that well in the zone only helps his case to get promoted to the majors, and it’s also a good predictor of how he might fare if/when he assumes a regular role there. He’s able to achieve this effectiveness in the zone with a devastating fastball that sits around 96 mph and 2,500 RPMs with a very impressive 17.5 inches of ride, or induced vertical break. There’s a lot to like here, as he’s able to generate chase and swing-and-miss out of the zone on top of what he can accomplish while still living in the zone.
The Guardians fielded a monstrous bullpen in 2024 which only appears to have gotten better over the offseason, and that goes for both internal and external additions. Walters should get a fair shot at contributing to some degree, and his minor league numbers only add intrigue to what he can accomplish during his first full big league season.
4. Noah Cameron, LHP (KC)
Key Stat: +7 Run Value on Changeup
Another sleeper prospect quietly rising through the minors, Cameron had a terrific season at Triple-A Omaha last year. The 25-year-old southpaw was a seventh-rounder in 2021 and was listed as Kansas City’s 14th-best prospect by Fangraphs this winter, but all of a sudden, there’s buzz about him potentially cracking the Royals’ rotation straight out of camp. If it happens, part of it would be out of necessity due to the team’s injury situation, but he nonetheless caused a stir over the weekend after showing up to spring training with a much harder fastball than what we’ve seen from him so far. Even last week when pitchers and catchers first reported, there wasn’t much of an indication that Cameron becoming a big-leaguer in 2025 was possible, and now a lot more people are starting to ask where he came from.
Again, he was effective all across the board with a 2.32 ERA and 3.39 FIP in nine starts at Triple-A, but when bucketing by pitch group, Cameron had the highest run value on off-speed pitches (+7) of anyone under 26 with a minimum of 100 BBE. The driving force behind that was his changeup, which is a slow, tumbling thing of beauty. This bad boy had hitters fooled all season long, garnering a 44.4% chase rate, 31.5% whiff rate, and a 40.9% groundball rate, without a single barrel given up against it.
Another thing that stands out about its shape is the horizontal approach angle – it approaches the plate at an angle that’s relatively quite straight-on despite Cameron frequently locating it on the corners. Interestingly, this is reminiscent of Tyler Anderson’s changeup, which was one of the best in the majors last year (+17 RV). Like Cameron’s, it’s also slow and doesn’t spin much. This should make for one of the better off-speed pitches in the game if Cameron gets the chance to show it off at the big league level, which he has not only earned after his performance at Triple-A but might just be needed if the Royals’ injured starters aren’t built back up a month from now.
5. Brandon Sproat, RHP (NYM)
Key Stat: 60.0% Pitcher Ahead Swing%
The Mets’ farm system has been somewhat compromised since Steve Cohen took control of the team, as they’ve been aggressively adding to the big league roster outside of that mini-sell at the 2023 trade deadline. It shouldn’t be overlooked, though, because they have a blue-chip pitching prospect in Sproat, a second-round pick from a couple of years ago. To say he shoved his start to his pro career would be an understatement – the former Florida Gator was promoted to Double-A after just 25.1 innings at High-A, and 11 starts later, he suddenly found himself in Triple-A.
It was there that he finally got exposed with a 7.53 ERA in seven starts. His strikeout rate nearly halved, and he was considerably snake-bitten by the home run ball. There’s a fair bit of noise in those results, though; as you can see, he wasn’t giving up a ton of barrels, which makes it seem like there was a decent bit of poor batted ball luck accounting for his inflated 22.6% HR/FB rate. Another thing that’s impressive about his time at Triple-A despite the poor results was the rate at which batters swung against him when they were behind in the count. It’s a good sign if a pitcher can induce swings while ahead in the count because that’s a scenario in which they aren’t likely to be giving their opponents anything good to hit.
Sproat’s arsenal is headlined by a four-seam fastball that averaged 96.7 mph during his stint at Triple-A and supported by a high-80s slider that’s more traditional in terms of movement compared to the sweepers that took the league by storm in the early 2020s. Recent news from the Mets’ spring training suggests that Sproat is also working on adding a two-seamer, which would be a nice “bridge” pitch if it works out considering the only offering he currently has with significant arm-side movement is a changeup. That development, as well as everything else he does for the rest of spring training, could prove to be very consequential, as New York’s rotation is slated to be without the hobbled Frankie Montas Jr. and Sean Manaea to start the year. Ideally, Sproat would get a little more runway in the minors to prove he can lean on his strengths to overcome the bumps in the road he faced once he got to Triple-A, a path that all teams would prefer to take with a prospect of this caliber. However, his MLB debut could be on the horizon much sooner than previously thought in light of the injuries to his colleagues. His spotlight for the rest of training camp just got much bigger. Let’s see how he handles it.