Harris impressed in the first half of 2024, with an unusual fastball shape that has helped him strike out more than 30% of hitters at every level
From undrafted free agent to being on the brink of a major league call up, the path for Hayden Harris has been an unusual, but impressive one. Harris has turned himself into one of the Atlanta Braves top prospects with a unique fastball that punches above its weight class.
How acquired
After spending five season at Georgia Southern Hayden Harris was receiving little recognition for the draft. As an undersized reliever with a upper 80’s to low 90’s fastball, a lack of college success, and no notable secondaries, Harris was passed on for 20 rounds in 2022. However, as recalled in this article from the AJC’s Justin Toscano Harris had done his leg work, utilizing LinkedIn to reach out to scouts and set up a pre-draft deal to sign with the Braves as an undrafted free agent. Harris had a mediocre debut in 2022, but exploded in 2023, first garnering attention when he struck out 15 batters in 8 1⁄3 innings with Augusta.
Preseason Report Card
Harris ranked 29th on Battery Power’s preseason top 30 list, and came into the season with as many questions as answers. Harris grabbed our attention along with the rest of the people covering the system with his unicorn fastball — a pitch that topped out around 92-93 and didn’t have unique movement, but which he threw from a low angle with elite extension and was able to blow it past hitters like it was mid-90’s heat. In 2023 Harris struck out an astounding 91 hitters, 36.8% of those he faced, and finished out 35 innings in Double-A with a 2.83 ERA/2.64 FIP/3.44 xFIP. A few big questions remained though. Would his fastball work against experienced, upper level hitters? Would he be usable against right-handed batters, whom he struck out 12% less often and gave up an isolated slugging more than twice as high in 2023?
What we saw in 2024
Harris answered some of his questions, and even a couple not asked, in 2024, dominating early before hitting a wall late in the season at Triple-A. In total Harris shifted nearly exclusively to single inning outings in 2024, and maintained his strikeout rate at the upper levels with a 35.9% strikeout rate overall on the season. Harris’s bug from college cropped back up though, as his walk rates skyrocketed to over 10% and then over 15% in Triple-A. From the beginning of the season to the end of July Harris posted a 38.6% strikeout rate and a 2.14 FIP, and his transition to Triple-A did come with walks and an increase to a 4.32 FIP in that timeframe, but he also maintained a 37.8% strikeout rate. August and September were brutal, however, as although his 30.8% strikeout rate is still solid he allowed four home runs and ten walks in 13 innings and ran a 9.00 ERA/6.80 FIP.
Let’s start with what went wrong for Harris, since poor play is our most recent impression of him, then zoom out and look at an overall dominating, if inconsistent 2024 season. Harris was working on things all season — notably a split-finger fastball — and as a result his numbers are a bit skewed as neither of his secondaries performed particularly well at any level. However, he still threw fastballs over 80% of the time and most of his issues did surround his fastball. One, hitters getting more chances to see him and knowing he’s going to throw fastball nearly every pitch certainly helps them, and especially right handed batters who had a .422 wOBA/.342 xwOBA against a .353 wOBA/.319 xwOBA from left-handed batters. Harris facing a higher percentage of right handed batters at Triple-A than at other levels, and throwing fewer secondaries against those batters likely widens the gap in these numbers.
Pitch usage, unfortunately, is just who Harris is a player. While there is some promise of keeping hitters off balance with his slider and splitter, his fastball is his bread and butter and it simply wasn’t as good in the second half of his time at Gwinnett. His fastball whiff rate halved and the barrel rate more than doubled, not a good combination of factors for a hitter. My view of this change from Harris likely boils down to fatigue. While he threw more innings in 2024 than in 2023 he made one major change, and that was an increase in velocity. This is of course a positive trend — he went from barely clearing the 92 mph mark to averaging over 92 mph in Triple-A, and his fastball early in his time in Triple-A was the best whiff-creating fastball in the league and showed 70 grade potential. At the end of the season his fastball drifted down in the zone more often, which is a dangerous position to be in given his velocity and spin metrics, and hitters took advantage of it. His command simply wasn’t good on the pitch, and when relying on throwing a fastball at the top of the zone to get outs one needs to be able to put that fastball on top of the zone. His pitches drifted down, took on more of a sinker shape towards the second half of the season, and it started to play like its velocity.
This isn’t uncommon for guys who see drastic jumps in fastball velocity in their first season. It takes more than one offseason to build up the stamina to go a full season at a higher effort tier, and you can look at another Braves prospect in AJ Smith-Shawver as an example of how those guys often finish. While Harris didn’t see a dip in his velocity his pitches drifting down, missing the zone more often, and losing spin shows a sign of fatigue that an offseason of rest should fix. Velocity is still not Harris’s only problem though. He has to figure out a way to get his changeup working a bit better against right-handed batters in order to have a real secondary to use. His slider wasn’t particularly good on its raw metrics, but by tunneling it with his fastball he is able to keep hitters from making solid contact and tends to get pedestrian numbers but numbers which allow his fastball a chance to breathe and not be sat on all the time. That simply wasn’t the case with his splitter, which showed neither signs of forcing weak contact or getting whiffs against right handed hitters, though his command of the pitch is suspect and he was learning it on the fly throughout the year. Our first indication that he was working on a splitter came to us in May, so we’re talking about a limited timeframe where he hasn’t had a chance to work closely with the major league staff yet.
So all of the negative performance out of the way, for four months this season Harris was the best relief pitcher in the system and showed off new levels of his fastball. While his walk rate did tick up it was more the effect of facing higher level hitters, which forced him to sit on the edges of the zone unlike what he did in the lower levels. Harris’s command, at least until the latter month of the season, was significantly improved over 2023 as he was dotting the top of the zone and just above the zone. Combined with the increased velocity and Harris improved two of his biggest yellow flags coming into the year, and overall despite the tough end my projections of Harris improved. Adding a third pitch has complicated things a bit as he didn’t have time to fully develop the pitch, but he needed a weapon against right-handed batters and if he is going to reach his ceiling that was a positive development that needs more time to play out. For a handful of games Harris showed off the best fastball in Triple-A, with both elite swing-and-miss and hard contact avoidance, and the next step will be him holding that performance through an entire season.
2025 Outlook
Harris’s goal for 2025 should be to end up in the major leagues at some point. He will likely not get a role out of spring training, though the loss of Joe Jimenez and potential departure of AJ Minter does open the door a bit, but he will have a chance to once again work closely with the major league staff on his mechanics and secondaries, and to put his name in the hat for a midseason call up. Harris should head out to Gwinnett and will likely spend most of his time there even if he does get a major league call up, and there will be three things I really focus on from him. First is sequencing. I do think Harris can survive at 70+ percent fastball usage, but his confidence in his secondaries and usage of them to get strikeouts on occasion would help him be less predictable. His command returning to his summer form is the second important point, and the thing I’m most confident in for Harris as his improvement last season certainly boded well. The final development will be his splitter, which needs to be better in order to give him a real second weapon against right-handed hitters. As he primarily relies on his release to create deception he will always have a much tougher time against right-handed hitters, and if he can’t develop a legitimate secondary to combat them sitting on his fastball it will be hard to get him into a major league role beyond just shuttling him in when the team needs garbage innings. Harris’s ability to soak up teaching and improve at the professional level gives some promise to his ability to master a changeup, but it will be closely watched and will make a major impact in whether he can get to a high-end middle relief/low end setup ceiling or will fade more towards the back of a major league bullpen.