Lamar Patterson is number 21 on the Atlanta Hawks.
Corey Jones wears No. 21 for North Melbourne Football Club Cameron Mooney wears number 21 for Geelong. Jason Akermanis wears No. 21 for the Western Bulldogs. Quinten Lynch wears number 21 for the West coast Eagles. Daniel Merrit wears No. 21 for Brisbane. GO LIONS
Currently, no player wears #21 for the Yankees.
Mike Jenkins (CB) currently wears number 21 for the Dallas Cowboys.
Nikolai Khabibulin was the goalie that wore number 34 for the hawks, but later changed it in a different season to number 39.
MANY
Eric Wright currently wears the #21 jersey.
Mike Jenkins
Jeff Teague
Tim Duncan
Marcus Camby but he got traded
Lucasz Fabianski wears the number 21 on his shirt