The Brief The Seattle Mariners have released their 2026 schedule. The Seattle Mariners have released their game schedule for next year, kicking off opening night in March 2026. Seattle Mariners opening night 2026First up, the Mariners will face off against the Cleveland Guardians for the home opener on Thursday, Mar. The schedule lays out all the games the Mariners will go to bat for through September 2026. A full look at 2026 dates can be found at the Mariners schedule page.