MLB's Pirates will honor Roberto Clemente by wearing his number

Why are MLB players wearing 21? Tributes around the league for Pirates legend explained

Five Astros wear No. 21 on Roberto Clemente Day

Roberto Clemente Award winners to wear cap patch

Puerto Rican players follow Pirates' push to wear No. 21, celebrate Roberto Clemente

New York Yankees' Aaron Judge waits on deck, wearing the number 21 in honor of Roberto Clemente Day, during the first inning of a baseball game against the Pittsburgh Pirates in Pittsburgh

Roberto Clemente's No. 21 is 'retired in our hearts' but not on most MLB rosters - The Athletic

MLB Clemente Award winners wear his 21 on caps for careers

All Puerto Rican players can wear 21 on Clemente Day

Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente - NBC Sports

Ríos, Hernández to wear uniform No. 21 on Roberto Clemente Day, by Rowan Kavner