What to Expect in Spencer Schwellenbach’s major league debut (2024)

If we’ve said it once we’ve said it 100 times: once you get to Double-A in the Atlanta Braves system you immediately become a candidate for a major league call up. There is overwhelming surprise around baseball at Atlanta’s decision to call up Spencer Schwellenbach — whose professional career is limited to jut 110 innings and whose Double-A stint lasted just two games. However should we be? The Braves have shown at this point that they are willing to call up anyone who they think gives them even the slightest edge, and with the injury to AJ Smith-Shawver (who I fully believe they wanted to hand the keys to) there is plenty of reason to think Spencer Schwellenbach is the next best option.

First let’s look at Schwellenbach himself. In the 2021 draft Schwellenbach wasn’t even universally considered a pitching prospect. Many evaluators loved Schwellenbach’s bat and athleticism at shortstop, but the Braves fell in love with him on the mound and the underlying data behind him. Schwellenbach dominated as a closer at Nebraska, and the Braves would have been fully prepared to take Schwellenbach in the first round until pre-draft medicals threw a red flag for his elbow. This slid him down to the second round, and even with the concerns the Braves were ecstatic to get him at this stage in the draft. The Battery Power staff agreed — from what we gathered from scouts we talked to and from the reaction of the Braves themselves we immediately had Schwellenbach in the top 10 of a system that was at the time much deeper. Even after Schwellenbach ultimately needed Tommy John surgery we placed him above the first round pick from that draft Ryan Cusick, and after a missing the rest of 2021 and all of 2022 there was immense excitement to see his Braves debut in 2023.

Early in the season last season Schwellenbach seemed quite far off from the major leagues. That could have been expected, he really only started pitching full time his junior year of college. However his talent was incredible, everyone in the organization loved Schwellenbach, and the scouts and underlying data supported the idea that his low whiff rates weren’t the concern they may seem to be. Even when injury truncated his rise and delayed his High-A debut, ultimately limiting him to 65 total innings last year there was still whispers of optimism surrounding Schwellenbach that far exceeded the raw performance on the field. 2024 Schwellenbach was the same guy but to the next step of his career. Starting out in High-A he was dominant, pitching to a 2.76 FIP and 2.53 ERA, but even though the raw stuff was there there was an air of concerns as he still didn’t miss bats at as high a rate as we had hoped. Then came his Double-A debut.

Let’s start here with a breakdown on Schwellenbach’s arsenal. Schwellenbach works with five pitches — a four seam fastball, a slider, a curveball, a splitter, and a recently added cutter that seems to have been successful in light usage this season. Schwellenbach’s fastball is fast, certainly, as he averages just over 95 mph on the pitch and has topped out at 99 mph, but it’s also been the pitch that has given some evaluators the most reason to pause. It’s shape is really below average, with plane and movement that don’t stand out and make the pitch a bit more hittable than the raw spin and velocity might indicate. Still, at Double-A the pitch looked a bit better, as although it wasn’t and won’t be a pitch that misses bats at a high rate his command has continued to take steps forward and he can really put the pitch in all four quadrants at will. Then come the breaking balls.

Schwellenbach’s slider and curveball are both plus pitches, and they play so well off of his fastball that he is able to put away hitters with remarkable consistency. His slider in particular saw limited usage at the lower levels - around 17% at High-A - but the raw data on the pitch suggest it is one of the better ones in the system and the scouting tends to support this idea. When the Braves promoted him to Double-A they allowed him to eat more with that slider, and in his two outings it showed as Schwellenbach piled up 17 strikeouts in 13 innings and was utterly in control of every batter he faced. Even in rotations flush with talent Schwellenbach stood out. Schwellenbach shared High-A with 1st round pick Owen Murphy and 2nd round pick Drue Hackenberg, then went to Double-A where he was grouped in with 1st round pick Hurston Waldrep and rising prospect Ian Mejia. At both stops he stood out as the most polished, as a guy who could put five pitches where he wanted to and had the secondary offerings to keep hitters guessing and unable to square up much of what he threw.

Schwellenbach’s splitter has been a pleasant surprise this season for him. My concern with this pitch is probably the greatest concern I have in his pitch mix and it’s his tendency to slow down his arm speed when he throws it. This makes it easy to read out of the hand and batters often are able to make contact at a much higher rate than the shape and velocity of the pitch might suggest. However Schwellenbach has a great feel for location the pitch at the bottom of and just below the zone, and when he matches arm speed it gives him another potentially above average look to throw at hitters. He will need to improve his arm speed on the pitch, but the pure quality of the pitch is there and over time there is plenty of reason to be confident in the pitch’s ability to combat left handed batters. Still though, I believe the curveball will get the most usage and is at present the best weapon he has against left handed batters. Schwellenbach’s cutter sees limited usage, but has high spin rates and impressive movement and as he gets more comfortable with the pitch it provides another look to his fastball to combat some of the issues with that pitch.

So back to the problem of him missing bats, and why that isn’t as big of a concern as it was for me even a few weeks ago. The Braves have quite regularly limited pitch usage for guys in an effort to have them develop their weaker pitches. In Schwellenbach’s case, and I want to emphasize this is speculation as I haven’t been able to confirm this with anyone in the organization, it seems that there has been an effort to limit the usage of his slider that was an absolute monster of a pitch in Double-A. He’s one of those guys, and everyone you talk to that has seen Schwellenbach pitch and has been around him believes that he is a special pitcher. I have no reason to dispute that opinion. His arsenal is above average and he mixes in fantastic command that is far above his experience level.

The question now is what do we expect from Schwellenbach and is this the right move for the Braves right now? Question number two - I think yes. Schwellenbach was probably going to be in Atlanta this season anyways as he has upcoming Rule 5 eligibility this winter, and he was already being promoted to Gwinnett after just those two starts. Disregard experience for a minute, if we’re talking the polish to pitch mix, command, and approach he is simply better right now than the guys he is competing with. Hurston Waldrep is a player I like, a great with a great mix of pitches and a great mentality. However he just isn’t ready, and rushing him probably isn’t worth it at this stage. AJ Smith-Shawver is hurt, and that leaves a handful of older prospects/veterans who simply aren’t as talented as Schwellenbach. Is he ready? No one ever is. Is he as close as it gets? Absolutely. He has handled every transition with absolutely zero trouble, and my only question is how long the Braves can utilize him. Last season he threw 65 innings, which was his career high. He is at 45 already this season. He hasn’t thrown more than 87 pitches in a game this season either. The Braves are handling him with kid gloves due to the concerns that he could run into more injury trouble, and we may find ourselves in a situation where he is having to be shut down in the second half of the season. Is it worth it though? I believe so. I don’t think Schwellenbach is going to dominate right away the way he has done at the minor league level. MLB hitters are just too good and Schwellenbach isn’t at the level of a guy like Spencer Strider. Long-term this is a guy I think could end up being a 2/3 starter, he is just that talented. Right now, if we’re talking about him as the fifth starter in the rotation what he provides is a guy that has the pure stuff to get major league hitters out along with the command and stability to keep himself out of trouble and keep a team in games. He has, by all reports, the mentality and poise to handle the inevitable struggles that come in a young major league career, and I know I am one of many who are absolute shaking with anticipation over his debut. He’s just one of those guys who has it, and I hope he can stay healthy and make the most of it. If you’re expecting an ace right away then be disappointed, but he is an upgrade over what the Braves have gotten from their fifth starter spot this season with the ceiling of a guy who can give the team innings in October.