Mariners win arbitration case against Diego Castillo

The Mariners have won their arbitration case with reliever Diego Castillo, reports Mark Feinsand of MLB.com. He’ll be paid at the team’s filing rate of $2.95M rather than his camp’s requested $3.225M figure.

Castillo has played a season-and-a-half in the Pacific Northwest. Acquired from the Rays at the 2021 trade deadline, he’s provided the M’s with 76 1/3 innings of 3.42 ERA ball. That includes a 3.64 mark over 54 1/3 frames last season, with the big righty striking out a solid 23.9% of opponents against a slightly elevated 9.9% walk percentage. That’s not quite the level he’d managed during his best seasons in Tampa Bay but has still made him a solid high-leverage option for manager Scott Servais.

He’ll again take on some key innings as part of what should be another strong Seattle relief unit. Andrés Muñoz, Paul Sewald, Penn Murfee and Matt Brash are among the other righties who could log key work. The M’s don’t have an established left-hander in the group — offseason waiver claims Tayler Saucedo and Gabe Speier are the only two lefty relievers on the 40-man roster — but the unit was nevertheless among the league’s top 10 in both ERA and strikeout percentage last season.

Castillo has between four and five years of MLB service time. He’ll be eligible for arbitration again next winter before qualifying for free agency over the 2024-25 offseason, at which point he’ll be entering his age-31 season. Seattle still has pending arbitration hearings with Teoscar Hernández and Dylan Moore.