why are the mets wearing 21

The Mets are wearing the number 21 to honor Roberto Clemente as part of MLB's celebration of Roberto Clemente Day. On this day, all players, managers, coaches, and umpires wear a "21" patch on their chests to recognize Clemente's legacy. Additionally, players of Puerto Rican heritage, past Roberto Clemente Award recipients, and nominees for the award have the option to wear the number 21 on their jerseys. The Mets, along with the Pittsburgh Pirates (Clemente's team), wear 21 to pay tribute to Clemente's remarkable career and humanitarian contributions. This tradition celebrates his life as a Hall of Famer, 15-time All-Star, and global humanitarian who died delivering earthquake relief supplies in 1972.