why is aaron judge wearing 21

Aaron Judge is wearing number 21 to honor Roberto Clemente, a legendary Puerto Rican baseball player who wore No. 21 throughout his career. MLB celebrates Roberto Clemente Day on September 15 each year, when players have the option to wear the number 21 jersey to pay tribute to Clemente's legacy both on and off the field. Judge wore number 21 along with other Yankees stars on this day to honor Clemente's impact on baseball and his philanthropic work.