Randy Johnson number retirement: Mariners to retire No. 51 during 2026 MLB season

The Seattle Mariners will celebrate the contributions of legendary lefty Randy Johnson by retiring his No. 51 on May 2, 2026, the club announced on Thursday. The celebration will take place in a pre-game ceremony at T-Mobile Park in Seattle. 

The “Big Unit” joined the Mariners via trade with the Montreal Expos in 1989. He went on to spend parts of 10 seasons in Seattle, and in that decade of work the 6-foot-10 Johnson went 130-74 with a WAR of 39.0. Johnson won the first of his five Cy Young awards as a Mariner in 1995. The M’s traded him to the Astros in a 1998 deadline deal, and Johnson went on to enjoy a legendary run with the Diamondbacks in his mid- to late-30s. 

Johnson retired following the 2009 season with a WAR of 103.5; 303 wins; 4,875 strikeouts; and 22 seasons in MLB. His WAR ranks ninth all-time among pitchers and he’s second only to Nolan Ryan in career strikeouts. Along the way, Johnson earned 10 All-Star selections — half of which came with the Mariners — and won the World Series MVP award with Arizona in 2001. He also has to his credit a pair of no-hitters and exactly 100 complete games. Johnson was elected to the Baseball Hall of Fame in 2015. 

Johnson will become the fifth player to have his number retired by the Mariners. He’ll join Ken Griffey Jr. (No. 24), Edgar Martinez (No. 11) and Ichiro Suzuki (who also wore No. 51 and had his number retired in 2025). As is the case with all of MLB’s 30 teams, the Mariners also retired Jackie Robinson’s No. 42.