Spencer Schwellenbach’s Emergence Is Huge For Atlanta

A lot has gone wrong for Atlanta this year. They came into the year as one of the best on-paper clubs. Prior to any regular season games being played, the Playoff Odds at FanGraphs gave them a 25.3% chance of winning the World Series and a 98.5% chance of making the postseason, both of those figures being the highest in the league.

It appears we may be living in one of the 1.5% of alternate universes where they don’t make the playoffs, as their season is currently on the brink. They are two games behind the Mets and 1.5 behind the Diamondbacks for the final two National League Wild Card spots with less than a week to play. They could still squeak in, especially as they’re hosting the Mets for three this week, but it’s going to be tight. That’s thanks to a combination of factors, as several players on the roster have either underperformed or missed significant time due to injury.

Things may have been even worse if not for a handful of positive developments. The Chris Sale pickup has worked out beautifully, something that MLBTR’s Steve Adams recently explored in a piece for Front Office subscribers. Signing Reynaldo López and moving him back to a starting role has also worked out well. Marcell Ozuna is having his best season in years. But they’ve also gotten a huge performance from rookie Spencer Schwellenbach, which is a big development for the club both this year and in the future.

Schwellenbach came into the year with fairly limited experience. The righty was drafted in 2021 but had Tommy John surgery afterwards, which kept him from making his professional debut until 2023. Once he was able to retake the mound, the results were strong. He pitched 65 innings on the farm last year, split between Single-A and High-A, allowing 2.49 earned runs per nine. He struck out 21.6% of opponents and kept his walks down to a 6.3% rate.

Another eight starts in the minors to start 2024, between High-A and Double-A, led to him getting a quick push to the majors. Atlanta had already lost Spencer Strider to season-ending UCL surgery and needed help in the rotation.

Schwellenbach was added to the roster and made his major league debut on May 29, just two days before his 24th birthday. He now has 19 starts under his belt and looks the part of a legit big league starter. In 109 2/3 innings, he has a 3.61 ERA. He has struck out 26.3% of batters faced and limited walks to a 4.9% clip.

Despite his fairly short track record as a professional, he seems to have a…