Predicting the White Sox Opening Day bullpen after Seranthony Dominguez signing

The White Sox, who finished 2025 with 100 losses for the third consecutive season, entered the offseason looking to make meaningful improvements to add to the win total. The team has added Munetaka Murakami to the lineup, and Anthony Kay to the starting rotation. Among the areas identified for improvement: the bullpen, which finished 2025 with a 4.16 ERA. This ranked 18th in baseball, and their season was defined by inconsistency. Jordan Leasure led the White Sox with just seven saves, and the team hasn’t had an established closer since Liam Hendriks. That changed this week, when the White Sox agreed to a two-year deal with RHP Seranthony Dominguez, who is expected to be the team’s closer in 2026. The full bullpen is yet to be decided, but with just two weeks remaining until Spring Training, let’s take a look at what the Opening Day pen could look like. 

Roster Locks: Dominguez, Taylor, Leasure, Newcomb, Vasil

The White Sox are likely to open the season with eight relievers, and I think five of them are set in stone, barring injury. The newly signed Dominguez and 2025 breakout pitchers Grant Taylor and Jordan Leasure are likely to serve as the team’s primary late-inning options. Mike Vasil held a 2.50 ERA in 100 innings last season and has shown the ability to produce in high-leverage, middle-relief, and multi-inning outings. He’ll be a valuable Swiss Army knife for the White Sox. Lefty Sean Newcomb will reportedly get a shot at cracking the starting rotation, but I’m not sold on his chances of making it happen. Newcomb posted a dominant 1.75 ERA in 36 relief appearances for the Athletics down the stretch last season, and hasn’t crossed the 100-inning since 2018. It’s hard to envision the White Sox relying on a guy with much more success as a reliever to handle a starter’s workload. I believe another starter will be added before the season begins, allowing Newcomb to slide into the bullpen where he can thrive. 

The Left-Handed conundrum: Gilbert, Eisert, Borucki, Murphy, Hudson

The White Sox are likely to keep three left-handers in their bullpen. It’s a breakdown they did often last season and seems to be a healthy way to balance arms. Assuming Newcomb is one, that leaves two roster spots for the likes of Tyler Gilbert, Brandon Eisert, Ryan Borucki, Chris Murphy, and Bryan Hudson. Gilbert and Eisert each spent significant time with the White Sox last season, with Gilbert producing the better results. Recently added Ryan Borucki gives the White Sox a grounder-heavy option, and the team was certainly intrigued enough by Murphy to trade for him back in November. Hudson is one year removed from a dominant 2024 season, but didn’t look the same in 2025. Ultimately, this decision could come down to minor league options. Brandon Eisert and Chris Murphy each have options, and Ryan Borucki’s minor league deal would allow him to be sent down. We’ll say the White Sox take the easiest path and keep all the options in their organization, adding Tyler Gilbert and Bryan Hudson to the big league roster to begin the season. 

50/50 shot: Paez, Alberto, Gonzalez

The wild card in this whole exercise is the presence of two Rule 5 picks in Alexander Alberto and Jedixson Paez. The White Sox can’t option either pitcher to the minor leagues or they’d risk losing them, but neither have thrown an inning above High-A and there’s not a clear spot available. In Alberto, the White Sox have what they believe is a future late-inning arm with a triple-digit fastball. Paez prioritizes control over stuff, making him a more natural fit as a future starter. It’s hard to envision the White Sox being able to keep both on the roster, so I’ll say they keep Paez and let Alberto go back to Tampa Bay. Wikelman Gonzalez, who showed promise in the bullpen in 2025, is likely the roster casualty here, but he’ll be one of the first names called in the case of an injury. 

Outside looking in: Cannon, Iriarte

Things look bleak for the other potential relievers on the White Sox 40-man roster. Jonathan Cannon and Jairo Iriarte are among the pitchers destined to begin the season in Triple-A. Iriarte has certainly shown major league caliber stuff, but needs to harness the command, and Cannon will look to take a step forward after a miserable 2025 season. Both may impact the big league roster at some point, but it’s highly unlikely it’ll be on Opening Day. Spring Training has yet to begin, however, so something could certainly change.