Gabriel James Speier, born April 12, 1995, in Santa Barbara, California, is an American professional baseball pitcher currently playing for the Seattle Mariners in Major League Baseball (MLB). Speier attended Dos Pueblos High School in Goleta, California, where he excelled as a pitcher and hitter, recording 87 strikeouts in his senior year and contributing to his team's league title. Although he initially committed to play college baseball at UC Santa Barbara, he chose to enter professional baseball after being drafted by the Boston Red Sox in the 19th round of the 2013 MLB draft[1][2]. Speier began his professional career in the Red Sox minor league system and was traded to the Detroit Tigers in 2014 as part of a deal involving major league pitcher Rick Porcello. He spent several years developing in the minor leagues, showing steady progress as a left-handed relief pitcher. Speier made his MLB debut with the Kansas City Royals on September 5, 2019, before eventually joining the Seattle Mariners[1][2][4]. Known primarily as a relief pitcher, Speier has established himself in the Mariners' bullpen. As of the 2025 season, he recorded a 2.61 ERA with a 0.87 WHIP in 62 innings pitched, reflecting strong performance and control. Over his major league career, he has appeared in over 215 games, with a cumulative 3.64 ERA and 214 strikeouts in 180 innings pitched. He is noted for his left-handed pitching and his role as a middle reliever[2][4]. Speier is part of a baseball family, being the cousin of former MLB pitcher Justin Speier and nephew of Chris Speier. His 2025 season included some injury challenges, notably a left rotator cuff strain that placed him on the injured list briefly, but he returned to active play after rehab[5]. Overall, Gabe Speier is a left-handed relief pitcher with a solid MLB track record, contributing consistently to the Seattle Mariners' pitching staff since his debut in 2019[1][2][4][5].