why are the jays wearing 21

The Toronto Blue Jays are wearing the number 21 jersey to honor Roberto Clemente. This is part of Major League Baseball's annual Roberto Clemente Day celebration on September 15, where players, coaches, and managers—especially those of Puerto Rican descent, award nominees, and past recipients of the Roberto Clemente Award—wear the number 21 jersey or patches bearing the number. Roberto Clemente, who wore number 21 throughout his career, was a legendary Hall of Famer and humanitarian. He passed away in 1972 while on a humanitarian mission, and every year MLB commemorates his legacy through this tribute. Blue Jays players like Vladimir Guerrero Jr., Bo Bichette, and others along with their manager and staff wear number 21 to honor Clemente's contributions on and off the field.