Starting in 2021, September 15th was declared Roberto Clemente day. All MLB teams wore a 21 patch on their sleeves, and players also had the option of wearing 21 as their uniform number.
Roberto Clemente Day
Starting in 2021, September 15th was declared Roberto Clemente day. All MLB teams wore a 21 patch on their sleeves, and players also had the option of wearing 21 as their uniform number.
Cardinals Uniforms & Logos 