SEATTLE -- The A's and Mariners joined the baseball community in celebrating Jackie Robinson Day on Sunday, collectively sporting No. 42 as part of a special tradition that dates to 2009.
The number was long ago retired by Major League Baseball, and on Sunday it was accompanied by additional uniform elements, including a commemorative patch on all team caps and jersey sleeves, and socks emblazoned with "42." All players and on-field personnel also received a lightweight hooded fleece for batting practice and dugout wear that featured the "42" logo.
MLB will donate proceeds from the sale of these items to the Jackie Robinson Foundation, which has continued Robinson's commitment to equal opportunity by addressing the achievement gap in higher education.