Mariners lefty Speier added to Team USA for WBC

Seattle Mariners left-hander Gabe Speier was announced as one of the latest additions to Team USA for this year’s World Baseball Classic on Wednesday.

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This will be the first time the 30-year-old Speier will compete in the WBC.

Speier, who the Mariners claimed off waivers from the Kansas City Royals in November 2022, has been a key member of Seattle’s bullpen and is coming off his best pro season.

The lefty reliever posted a 4-3 record, 2.61 ERA and 0.87 WHIP while holding opponents to a .192 average and striking out 82 batters in 62 innings over 76 appearances in 2025.

Speier’s career year came after injuries helped contribute to a rough 2024 campaign when he posted a 5.70 ERA and 1.39 WHIP in 23 2/3 innings over 29 games. When Speier debuted with Seattle in 2023, he compiled a 3.79 ERA and 1.06 WHIP in 54 2/3 innings over 69 appearances.

His 31.8% strikeout rate since the start of the 2023 season is 16th in the majors (minimum 140 innings pitched). Left-handed batters are hitting just .193 off him during that stretch.

Speier is one of three Mariners who have been officially announced as members of WBC teams. He’s set to join catcher Cal Raleigh on Team USA, while left fielder Randy Arozarena will compete for Team Mexico. Sportsnet reported first baseman Josh Naylor and reliever Matt Brash will compete for Team Canada alongside former M’s starting pitcher James Paxton.

Center fielder Julio Rodríguez (Dominican Republic), outfielder Dominic Canzone (Italy), utilityman Miles Mastrobuoni (Italy), starting pitcher Luis Castillo (Dominican Republic), closer Andrés Muñoz (Mexico), reliever Eduard Bazardo (Venezuela), starting pitcher Jurrangelo Cijntje (Netherlands) and second baseman/left fielder Michael Arroyo (Colombia) are among Seattle’s other candidates for the event. Rodríguez, Mastrobuoni and Arroyo each competed in the 2023 WBC.

Tampa Bay Rays right-hander Griffin Jax was also announced as a new member of the U.S. squad on Wednesday. The World Baseball Classic begins March 5 with the championship game slated for March 17 at loanDepot Park in Miami. Team USA starts play in Pool B with Mexico, Italy, Great Britain and Brazil.

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