The Mariners strengthened their bullpen depth by adding veteran reliever Scott Effross on a minor league deal The Seattle Mariners have added another experienced arm to their pitching depth, signing veteran right-handed reliever Scott Effross to a minor league contract. The move, finalized on August 12, gives Seattle another experienced option to develop at the Triple-A level while providing additional insurance for its major-league bullpen. MLB’s transaction log confirms the signing.
Effross, 32, brings 88 games of major-league experience dating back to his debut in 2021. He became known as a sidearm-style reliever during his time with the Chicago Cubs and later pitched for the New York Yankees. His experience gives Seattle a pitcher who has already faced major-league hitters and understands the demands of a bullpen role.
The signing comes after Effross spent the 2026 season in the Detroit Tigers organization. He worked primarily at Triple-A Toledo, where he recorded a 4.46 ERA, a 1.49 WHIP and a 26-to-9 strikeout-to-walk ratio across 36⅓ innings. Those numbers are not dominant, but his strikeout-to-walk production suggests there is still something for Seattle to work with.
For the Mariners, the most important part of the move is the depth it provides rather than an immediate addition to the major-league bullpen. Effross is expected to work with Triple-A Tacoma, where he can attempt to regain consistency and potentially put himself in position for a call-up if Seattle needs another reliever.
Seattle’s decision also makes sense from a roster-management perspective. A minor league contract allows the Mariners to add an experienced pitcher without immediately committing a major-league roster spot. If injuries or performance issues create an opening in the bullpen, Effross could have an opportunity to compete for that spot.
There is also some upside because Effross has previously shown that he can contribute at the major-league level. His unusual delivery can give hitters a different look, something that can be valuable for a bullpen that needs multiple styles of pitchers.
However, this should not be viewed as a major shake-up of Seattle’s bullpen. Effross will first need to prove that he can consistently get outs at Triple-A before the Mariners consider bringing him to the majors. His 4.46 ERA in Toledo shows that there is still work to do.
Still, the move is a sensible depth addition for Seattle. Rather than waiting until an injury creates an emergency, the Mariners have brought in a veteran who can compete for an opportunity while providing insurance behind their current relievers.
If Effross can rediscover the form that made him a useful major-league setup option earlier in his career, the signing could eventually become more significant than a simple minor league transaction. For now, though, Seattle is adding experience and another potential bullpen option without taking a major risk.
The Mariners will hope Effross can use his time with Tacoma to rebuild his consistency and earn his way back to the majors. For a team navigating the final stretch of the season, having another experienced arm waiting in Triple-A could prove valuable if the bullpen suddenly needs reinforcements.
