In Bummer Move, Braves Land Lefty Reliever for Pile of Ex-Prospects

Late Thursday night, after the final horn had sounded on the last West Coast NHL game, new White Sox general manager Chris Getz consummated his first trade in his new role, sending sinker-balling lefty reliever Aaron Bummer to Atlanta for a five-player variety pack of “second division” players and reclamation projects. The new White Sox are headlined by 26-year-old 2019 All-Star righty Michael Soroka, 28-year-old infielder Nicky Lopez, and 25-year-old lefty starter Jared Shuster, all of whom can be reasonably expected to impact the 2024 squad. Chicago also acquired 25-year-old infielder Braden Shewmake, who is also on the 40-man roster, and 2023 undrafted free agent starter Riley Gowens, who is more of a developmental project from the University of Illinois.

Let’s talk about the Braves’ end of this trade first. Most folks reading this are probably familiar with Bummer, a well-established lefty reliever who has been a middle-inning stalwart for the Pale Hose for the last half-decade. His velocity took a leap in 2019, and his re-worked breaking ball helped him elevate his game again in ’21. He is coming off a season in which he posted a 6.79 ERA and career-worst 13.5% walk rate, but from a stuff standpoint, he more or less looked like himself, and Chicago’s poor infield defense did him no favors. His fielding-independent statistics hovered around a much more respectable 3.50, consistent with his career norms.

We can look at this trade from a certain point of view and wonder why the Braves traded five players for a middle reliever, let alone one with an ERA near seven and who has posted two consecutive seasons with fastball velocities below his 2019–21 peak. But when you’re the Braves and have few holes to fill, you can pay a premium for a unique weapon, even if that weapon is likely to be deployed in medium-leverage middle innings.

And Bummer is indeed special in a few regards. Since he debuted in 2017, his 66% ground ball rate is second among all MLB pitchers who have worked at least 250 innings during that span. He and Clay Holmes (66.7% GB%) are in a tier of their own at the top of that list, with lefty reliever T.J. McFarland (63%) a relatively distant third. Bummer’s career ground ball rate is exceptional even though it was “only” 58% in 2023, which is somehow low for him despite being 16 points higher than the MLB average. The sink and tail on the low-slot lefty’s fastball makes it incredibly difficult for hitters to elevate; he has allowed a barrel rate below 3% in two of the last three seasons. That’s despite him allowing a fairly high hard-hit rate (44% in 2023, in MLB’s 11th percentile), which helps illustrate just how difficult it is for hitters to get underneath his sinker. And while Bummer does get hit hard, it’s barely ever in a way that actually results in damage.

With A.J. Minter already in place and Tyler Matzek scheduled to return from Tommy John, the left-handed contingent of Atlanta’s bullpen looks to be pretty nasty. Bummer will make $5.5 million in 2024, after which Atlanta holds two club options, one for $7.25 million in ’25 and one for $7.5 million in ’26. If he continues to pitch as he has for the last several seasons, Atlanta will exercise those options. It’s plausible that he might yet have another gear, and that the Braves might already have a tweak or two in mind that will help accentuate his skills. They’ve demonstrated a more consistent ability to max out their players than the White Sox have, and similar to the way it took tweaks by the Yankees to unlock Holmes’ ability, it’s fair to wonder if there’s developmental meat on the bone here that Atlanta can see from afar. He fits as a premium middle-inning “heir,” the reliever who often inherits runners because he’s the most likely to get the ground ball that produces a rally-killing double play.

As good as Bummer is, it isn’t as if any individual reliever could significantly alter the near-term fortunes of the White Sox, nor the long-term trajectory of the franchise. They need a significant reshuffling and a lot of help, and so it’s a process-oriented win for them to flip a middle-inning guy for a bunch of players who might contribute to a longer-term cause. Did they pick the right collection of players? It’s impossible to know what their alternatives were or who might have been on the table in other offers, but this return is definitely more about role-playing depth than upside.

The most-known player coming to the South Side is Soroka. The Canadian righty was a big time prospect who, at his age-21, 4-WAR peak, looked like he might be the second coming of Brandon Webb. Since then, the now–26-year-old has dealt with a myriad of severe injuries, including two Achilles ruptures that cost him two entire seasons and shoulder inflammation that ended his 2023 comeback campaign. He has always been more of a command-oriented innings-eater with good secondary stuff rather than a world-beating power pitcher, and with the Braves in win-now mode, they’re not really in position to let the option-less Soroka sink or swim at the big league level as part of their 2024 rotation, assuming he’s even healthy. The White Sox, however, have a much longer, lower-stakes runway to find out if he can be healthy and effective once again. Even if he can’t, his reputation as a hyper-competitive badass (I guarantee Soroka knows Mike Nikorak’s career stats) might help the new Sox regime build a more competitive clubhouse culture as the team navigates a few seasons of rebuild and transition.

If Soroka can stay healthy, then he and all but one of the pieces coming back to Chicago are likely to wear a big league uniform throughout 2024. Lopez was squeezed out of Kansas City’s talented young infield and traded to the Braves last season to shore up their thin middle infield contingent but was relegated to seldom-used bench duty during their playoff run. He is easily the best defensive infielder on Chicago’s roster and at this moment should be penciled in as the starter at shortstop. His huge 6-WAR 2021 season was largely driven by an unsustainably high BABIP, and he has since settled in as a high-contact, slick-fielding utility man with bottom-of-the-scale pop. On a contender, he would be relegated to a role similar to the one he played in Atlanta, where he was the team’s fifth infielder, capable of filling in at any infield position, and used situationally on offense when the club badly needed a ball put in play. His versatility will allow the White Sox to keep him in the lineup consistently and move him around the diamond so their young group of Latin American infielders — Lenyn Sosa, Bryan Ramos and José Rodriguez chief among them — can get sufficient big league reps and be well-evaluated ahead of Colson Montgomery’s eventual arrival.

The White Sox also acquired two former Braves first round picks who made their big league debuts in 2023 in Shuster and Shewmake. There was a brief period a few years ago when Shuster was throwing significantly harder than he has of late, likely due to extra rest and lighter workload created by the pandemic shutdown in his draft year. For the last several seasons, he has been a changeup- and command-oriented lefty with well-below-average fastball velocity. Perhaps because he’s had to nibble more with his vulnerable fastball as he’s climbed to Triple-A and MLB, his walk rate rose to a concerning 12% in 2023, much higher than his career norm; his strikeout rate also dropped to a career low. His slider usage has surpassed his changeup usage not because it’s become his best pitch, but because you need a non-fastball way to get ahead of hitters when you’re sitting 91 mph. Lefties with changeups as good as Shuster’s screwball-style cambio and command on the level that he has historically shown tend to have long, productive MLB careers, and I think it’s fair to hope for a bounceback.

The other interesting element Shuster might bring is a sort of institutional knowledge that the White Sox may yet lack. Wake Forest, his alma mater, is among the most advanced collegiate programs when it comes to using data and technology to help develop pitchers; the Braves also appear competent in this regard. Perhaps he will bring some of that with him in a way that has a long-term impact on Chicago’s implementation of these concepts, which may be held up due to a lack of willingness to invest in them at the ownership level rather than a lack of understanding in the front office.

This was an interesting buy-low opportunity for the White Sox who, if Shuster can become the no. 4/5 starter I projected him to be as a prospect, will on his own be a more valuable piece to the next good Sox team than even a special middle reliever like Bummer would have been. I think the three players I’ve discussed in depth to this point — Soroka, Lopez and Shuster — are the primary return in this deal, a piece for each year of team control Bummer has remaining.

I’ve never been especially high on Shewmake, who was drafted with the hopes that he’d add meaningful strength and weight to his lanky frame and remain at shortstop while maturing into meaningful power. He’s fundamentally sound at short, but I wouldn’t call him an impact defender there, and he’s remained skinny and hasn’t put together an impressive offensive season above Low-A. If anything, I think he clogs and clouds Chicago’s infield mix in an unnecessary way. He’d have been a fair upper-level depth option for Atlanta, which is once again very thin on viable middle infield defenders, but perhaps the Braves value the freed-up 40-man spot more at this point.

Finally, the White Sox acquired Gowens. The University of Illinois product missed his 2019 freshman year and the little bit of pre-shutdown 2020 because of an early-2019 Tommy John, which meant he was a draft-eligible redshirt freshman in 2021. Unselected in ’21 and ’22, he had a little velo spike in ’23 and was sitting more 92–94 and touching 96 than the pedestrian 90–92 he had shown in previous seasons. His fastball also has uphill angle and bat-missing carry. The White Sox will be tasked with teasing a better slider out of him, as his current 82–85-mph version is short and lacks depth.

This move fills Chicago’s 40-man roster for the moment and cleared a ton of space on Atlanta’s; the Braves now have three open spots. At some point this offseason, they’ll need to address the relative lack of viable middle infielders in the org, but adding Bummer helps fortify their already excellent bullpen.