M’s GM details role Seranthony Domínguez will play in bullpen

The Seattle Mariners’ trade of Luis Castillo to the Chicago White Sox impacts the bullpen in two ways.

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First, the departure of Castillo returns the Mariners to a traditional five-man starting rotation as opposed to the six-man rotation they had been using, allowing them to put another arm in the bullpen for the remainder of the regular season. And second, that extra arm was acquired in the Castillo trade with veteran Seranthony Domínguez coming to Seattle from Chicago.

The 31-year-old Domínguez gives the Mariners a hard-throwing right-hander with experience both closing games and pitching in the postseason. This year, he has a 3.99 ERA with 12 saves, while last year in the playoffs he had a 3.18 ERA with 10 strikeouts over 12 appearances (11 1/3 innings) for the Toronto Blue Jays, including 4 2/3 innings of one-run ball in five outings in the World Series.

Mariners general manager Justin Hollander provided insight on the team’s addition of Domínguez when he joined Seattle Sports’ Wyman and Bob just hours after the MLB trade deadline passed Monday.

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“He fits into our bullpen great. Really experienced leverage reliever,” Hollander said. “… Seranthony’s pitched in a lot of big games. Really tough right-on-right guy, has big velocity. The best version of him can absolutely pitch late in games in leverage.”

As for how Domínguez fits into the M’s bullpen, Hollander said he’ll be put into a “pivot” role and will take pressure off of Eduard Bazardo, who has been used 52 times this season after making a combined 82 appearances between the regular season and playoffs for Seattle in 2025. The importance of Bazardo has only been heightened this year with Matt Brash and Carlos Vargas on the injured list.

“He fits into that pivot role, and it (allows) us to not have Eduard Bazardo warm up every single night to face the right-handed pocket,” Hollander said. “We’ve worked ‘Zardo’ really hard this year, especially with Brash and Vargas being down.

“… I think with as good as our bullpen is at the back end, (Domínguez) will probably be pitching more mid-leverage for us. So coming into a game when the starter needs to get picked up in the middle of an inning, particularly against a right-handed pocket, folding in with that group between Bazardo and (Michael) Rucker. … Just giving us another experienced option as we get towards the playoffs and get a little healthier as the month goes on.”

Hear the full Wyman and Bob conversation with Mariners GM Justin Hollander in the podcast at this link or in the player below. Catch Wyman and Bob from 2-7 p.m. weekdays on Seattle Sports.

Seattle Mariners news and more

• Brock and Salk: Mariners get ‘big upgrade’ in Taylor Ward trade
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• A closer look at Seattle Mariners’ haul from Luis Castillo trade

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