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.

Several players took to social media to express their admiration for Robinson, who broke the game's color barrier when he took the field for the Brooklyn Dodgers on April 15, 1947. A's catcher Bruce Maxwell was among them, saying, "This man is the reason I play."
Mariners center fielder Dee Gordon also has a deep appreciation for the Hall of Famer, who inspired others to challenge the status quo.
"It means a lot to me," Gordon said. "I know I couldn't handle it. Being professional athletes, we can barely handle anybody talking trash to us on social media. For him to go through what he did every day. … I wouldn't have been the guy to do it. So I really appreciate him, and my family does as well."

Ever since Ken Griffey Jr. donned a No. 42 jersey on April 15, 1997, the Mariners have been at the forefront of Major League Baseball's efforts to make Jackie Robinson Day special.
Griffey swapped his No. 24 to 42 when the Mariners played the Indians in '97, then presented the idea that all players do so to former Commissioner Bud Selig a decade later.
As part of Sunday's celebration, Seattle hosted a pregame ceremony and presented the Most Valuable Diverse Business Partner Award to Cochran, Inc., a female-owned electrical and technology infrastructure contractor that has worked extensively with the Mariners at Safeco Field.