If Tuesday was the last start of Spencer Schwellenbach's season, he gave us yet another reason to be extremely excited about what the future holds.
In the first of what are effectively six win-or-go-home games for the Braves, Schwellenbach limited the Mets to just one run over seven innings of work, allowing just three hits and a walk in the 5-1 win. Schwellenbach may still make one more start this weekend in the season finale in what could be another must-win game for the Braves in Game 162, and at this point, there might not be another pitcher they'd rather have on the mound for it.
It's been an almost unbelievable breakout season for Schwellenbach, who has gone from not even being a top-100 prospect before the season to being someone I might be ranking as a top-30 starting pitcher for 2025. How did he get here, and was there something the prospect hounds missed with Schwellenbach?
To answer the second question first, I really don't think this one should count as a miss. In fact, Schwellenbach arguably counts as a win for the prospect folks, who had to do an awful lot of projecting just to get him into the top five of the Braves system. He was very good in 2023, to be clear, but was also a converted collegiate reliever who threw just 65 innings that season, his first back from Tommy John surgery. A 2.49 ERA across 65 innings as a 23-year-old in A-ball isn't nothing, but it didn't necessarily suggest an imminent, impact major-leaguer lurked in the profile – especially when he struck out just 55 batters.
But Schwellenbach is a tremendous developmental success story for the Braves organization, in much the same way Spencer Strider was before him. And, while I don't think Schwellenbach necessarily has that kind of upside, I do think the ceiling is sky-high here.
How high? Well, let's start with some superlatives. Among pitchers with at least 100 innings pitched this season, his 4.9% walk rate entering Tuesday's start was the 13th-best mark in baseball, while his 26.3% strikeout rate was good for 27th; only Logan Gilbert, Joe Ryan, and Tarik Skubal were better in both regards. So, he gets a lot of strikeouts and doesn't walk many batters; good start! And his 13.8% swinging strike rate was also the 12th-best in baseball, a sign that there might be even more strikeout upside than his already quite good overall mark.
Add in average results on balls in play, and you have a 3.45 xERA that is actually slightly better than his 3.61 ERA entering Tuesday's start – unfortunately, xERA doesn't update until the day after, so we don't know how much it improved with this outing. But, considering Schwellenbach only allowed three batted balls with an expected batting average over .500 Tuesday, it seems safe to assume that would have dipped even lower, too. That 3.45 xERA was good for 24th in the majors, just between Michael King and Yoshinobu Yamamoto, which is pretty good company to keep.
And the thing is, Schwellenbach might even have some room to grow. He has uncommonly good command of a full six-pitch arsenal for someone with as little experience as he has, and he might not even be maximizing that arsenal yet. His curveball and splitter have both been borderline elite pitches, sporting whiff rates of 39.7% and 46.9%, and it's not unreasonable to think he could see a spike in his (already good!) strikeout rate by leaning on those two pitches even more after throwing both less than 15% of the time this season.
Of course, that lack of experience is the other edge to this sword. Schwellenbach threw just 31.2 innings in his lone healthy season in college, and then tossed just 65 in 2023. That means that his 160.2 innings this season are by far the most he has ever thrown in a season, and that number will only climb if he makes another start this season – he could throw 100 more innings than last season by the time we're done, especially if the Braves make the playoffs.
There's no simple answer for how many innings a pitcher should increase from one season to the next – the so-called "Verducci Effect" has been, if not discredited, certainly overstated – but it stands to reason that a 100-plus inning jump from a young pitcher is a red flag, especially when that pitcher has never come close to that level before. Now, the fact that Schwellenbach has more or less continued to pitch at a high level this deep into the season does offer some evidence that the workload isn't catching up to him. But is it a reason to downgrade Schwellenbach in 2025 drafts? I think, combined with his history of injuries and overall lack of track record, that's probably justifiable.
But here's the thing: If you were just taking what Schwellenbach has done this season at face value and the upward trajectory he seems to be on, you could make a pretty compelling case that he deserves to be drafted as a top-20 starting pitcher for 2025. He had been a top-28 SP since his debut before Tuesday's gem, after all, and that was with a 5.68 ERA in his first six starts; he's been top-15 since July 1.
So, what's a good spot to rank Schwellenbach for 2025, taking into account both the obvious upside and the risk inherent in his profile? I haven't gotten through my SP rankings, but I plan on having them finalized by next week, and I think Schwellenbach will come in around the top 30. Maybe 24th. Maybe 34th. It's a distinction without a difference in that range, ultimately, and I might just opt to be more aggressive so I can plant a flag.
Because I do think there are some outcomes in 2025 where Schwellenbach outperforms the likes of George Kirby and Logan Gilbert and pitches his way into the top 12 backed by what should be a resurgent Braves lineup. In fact, I think the chances of that happening are relatively strong enough that even a top-24 ranking might not feel aggressive enough. Especially since, while he certainly has more risk than your typical pitcher ranked that high, the baseline level of risk is always so high that there's only so much you can actually do about guarding against injury risk.
I'll let you know where he ends up when I release my first way-too-early rankings next week, but suffice it to say I want Schwellenbach on my rosters for 2025.
