Mets honor Roberto Clemente at Citi Field
Why are MLB players wearing 21? Tributes around the league for Pirates legend explained
Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente
Pirates Celebrate Roberto Clemente Day, WESB B107.5-FM/1490-AM
Rangers, MLB honor late Hall of Famer Roberto Clemente with uniform patch, jersey numbers
Roberto Clemente - Wikipedia
Pirates would again like to wear No. 21 in 2021
Pirates will wear Roberto Clemente No. 21
All Pirates Wearing #21, Rest of MLB Wears Patches in Honour of Roberto Clemente – SportsLogos.Net News
Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente - NBC Sports
Oakland A's: Happy Roberto Clemente Day! - Athletics Nation
Should Roberto Clemente's #21 Be Universally Retired Across MLB?
Members of Red Sox wear No. 21 with pride on Roberto Clemente Day - The Boston Globe
Entire Pirates team will wear No. 21 to honor Roberto Clemente
For the 'Great One'; Pirates, MLB honor Roberto Clemente