The New York Mets are wearing the number 21 to honor Roberto Clemente on Roberto Clemente Day, observed by Major League Baseball around September 15 each year. Clemente, a Puerto Rican Hall of Famer and humanitarian, wore No. 21 throughout his career. On this day, all players, managers, and coaches have the option to wear No. 21 or a "21" patch to celebrate his legacy both on and off the field. This tribute also coincides with Hispanic Heritage Month and highlights Clemente's impact as an inspiration to Latino youth and the community. The Pittsburgh Pirates, Clemente's longtime team, and other MLB teams and players participate in this honor as well.