why are the mlb players wearing 21

MLB players are wearing the number 21 to honor Roberto Clemente, a legendary Puerto Rican Hall of Famer who wore No. 21 throughout his career. September 15 is celebrated as Roberto Clemente Day in Major League Baseball to commemorate his life, achievements on the field, and humanitarian efforts off the field. All MLB players, managers, coaches, and umpires wear a No. 21 patch on their uniforms on this day, and players of Puerto Rican heritage, Clemente Award recipients, and nominees have the option to wear No. 21 on their jerseys. This tribute coincides with the start of National Hispanic Heritage Month and celebrates Clemente's lasting impact on baseball and communities.