Juan Soto is wearing number 21 in honor of Roberto Clemente Day, when Major League Baseball players, managers, and coaches wear the number 21 to celebrate and recognize the legacy of Roberto Clemente. Clemente was a legendary Hall of Famer and humanitarian who wore No. 21 during his career and is celebrated for his sportsmanship, community involvement, and contributions both on and off the field. On this day, players of Puerto Rican heritage, past Clemente Award recipients, and nominees have the option to wear No. 21 as a tribute. Soto, along with other players, wears 21 as part of this league-wide recognition of Clemente's impact and legacy.