Houston Astros: 8 players don No. 21 on Roberto Clemente Day
Roberto Clemente and Martin Luther King Jr.: In Service of Others – Society for American Baseball Research
Puerto Rican Twins don No. 21 in tribute to Roberto Clemente – Twin Cities
MLB honors Roberto Clemente in 21st annual event
MORE
Some MLB Players Wearing #21, All Wearing 21 Patches Today for Roberto Clemente Day – SportsLogos.Net News
Rivera] League source confirms league-wide retirement of Roberto Clemente's #21 is not happening at this time and there is no current plan in place for it to occur : r/baseball
Roberto Clemente day: Puerto Rican MLB players, Pirates wear No. 21
Cristian Javier leads Astros to World Series history with combined no-hitter – Latino Sports
Report: Puerto Rican MLB Players Allowed to Wear No. 21 on Roberto Clemente Day, News, Scores, Highlights, Stats, and Rumors
Marley Rivera] Beginning today, all eight active Roberto Clemente Award winners will wear a No.21 on the back of their caps. This includes Nelson Cruz, Yadier Molina, Adam Wainwright, Albert Pujols, Carlos
Houston Astros: 8 players don No. 21 on Roberto Clemente Day
Díaz homers in 7th to break tie, Astros beat A's 5-2
Que Viva Clemente! Roberto Lives On in the Hearts of Latino Major Leaguers – Society for American Baseball Research
Uniform number (Major League Baseball) - Wikipedia