On May 16, the Mariners and Red Sox will honor the Negro Leagues with a special Turn Back the Clock night. Seattle will wear the uniforms of the Seattle Steelheads while Boston will don the jerseys of the Boston Royal Giants.
The Steelheads were members of the West Coast Negro Baseball League, which formed in 1946. Despite originally planning a 110-game season against teams in five other cities, the league folded after just two months.
The Mariners honored the Steelheads during a Turn Back the Clock night during the 1995 season, but did not have any photos to go off of to design the uniforms.