Ahead of the 2026 MLB Trade Deadline, former Toronto Blue Jays reliever Seranthony Dominguez was traded by the Chicago White Sox to the Seattle Mariners. He was one of the pieces the White Sox flipped to land star pitcher Luis Castillo from the Mariners. Overall, he was having trouble living up to the two-year, $20 million contract he signed with the White Sox during last offseason. Why former Blue Jays' Dominguez could heat back upWhen looking at how effective Dominguez was just last season for the Blue Jays, there is reason to believe that he can get things back on track with the Mariners. He also posted a 2-0 record, a 3.18 ERA, and 10 strikeouts in 12 appearances for the Blue Jays during their playoff run last year.