Reliever Seranthony Dominguez is off the board. One of the best relievers still on the market as of mid-January, Dominguez has reportedly agreed on a two-year deal to join the Chicago White Sox. The right-hander spent 2025 between the Baltimore Orioles and Toronto Blue Jays.
A Look at Dominguez
During the Blue Jays’ run to the 2025 World Series final, Seranthony Dominguez played a key role. Toronto acquired him last July in a trade with the Orioles, a deal that cost the Jays high-prized pitching prospect Juaron Watts-Brown.
Dominguez posted a 3.00 ERA with the Jays over 21 innings, striking out 25 batters. He then posted a 3.18 ERA and struck out 10 over 11.1 IP in the playoffs. However, it wasn’t a very clean run for him in October & November. Dominguez walked 11 batters in that span.
Overall, Dominguez struck out 79 over 62 innings between the O’s and the Blue Jays. He ranked well above-average in terms of Whiff% (33.3%), and his opponents’ wOBA of .280 was above the league median in terms of relievers who pitched in at least 30 games last season. His 5.2 BB/9 in 2025 ranked in the bottom-25 of the league.
The new White Sox pitcher is a hard-throwing reliever who topped out at 100 MPH last season. He has two primary fastballs, a four-seamer that was used significantly more in 2025, plus a sinker to jam in on right-handed hitters.
Dominguez changed up his arsenal between 2024 and 2025. Before last season, the 31-year-old’s main secondary offering was a slider, a pitch he used alongside a sweeper, sinker, and rarely-used changeup.
For 2025, he ditched the slider and changeup altogether. Instead, he relied more on a sweeper and broke out a splitter that sat in the mid-80s, giving him a new weapon to separate off the fastball.
That splitter, which had a Whiff% north of 49% last season, gave Dominguez a big option to use against left-handed hitters. However, opposite-sided hitters were still a sore spot for the veteran reliever.
Opposing right-handed hitters slashed .132/.269/.182 (.451 OPS) off Dominguez last season. Left-handed hitters fared significantly better. Those individuals slashed .277/.371/.446 (.816 OPS) off Dominguez, with four of the five home runs he allowed coming from those left-handed hitters.
Per reports, including MLB.com, the White Sox will sign reliever Seranthony Dominguez to a two-year deal worth $20MM.
Analysis
White Sox general manager Chris Getz stated after the trade of Luis Robert Jr. that he expected to be active in his search for additional talent. And shortly thereafter, Chicago came away with one of the best relievers still available on the market.
Dominguez becomes another notable addition to the White Sox’s bullpen. Earlier this winter, the team signed lefty Sean Newcomb, who excelled last season with the Athletics in a relief role, to bolster a young bullpen.
Many of the relievers currently on the 40-man roster, including Jordan Leasure, Wikelman Gonzalez, Brandon Eisert, and Grant Taylor, are under the age of 30.
Now that latter point may not mean too much in the grand scheme of things. What does matter is that Dominguez will give teams a different look. Leasure and Taylor are both high arm slot relievers who throw hard, with the latter being more of a flamethrower.
While Dominguez throws hard, as well, his arsenal is more nuanced and able to handle both lefties and righties. Plus, it’s a different look from a lower arm slot, which does matter in today’s day and age.
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