Why are MLB players wearing 21 on their sleeve? - Quora
To Pirates catcher Michael Perez, wearing No. 21 'very special
MLB allows more players to wear No. 21 to honor Roberto Clemente – NBC Sports Chicago
MLB Clemente Award winners wear his 21 on caps for careers
UNC Baseball: Jacob Stallings reflects on 2021 season
Roberto Clemente Day celebrated around MLB in 2023
Some MLB Players Wearing #21, All Wearing 21 Patches Today for Roberto Clemente Day : r/sportsthreads
Report: Puerto Rican MLB Players Allowed to Wear No. 21 on Roberto Clemente Day, News, Scores, Highlights, Stats, and Rumors
Five Astros wear No. 21 on Roberto Clemente Day