1980 - WR John Jefferson
1984 - TE Bobby Micho
1985-1986 - WR Trumaine Johnson
1988-1993 - WR Anthony Miller
From what I've researched, no one wore number 21 for the San Diego Chargers in 1998.
Most players never wore a chargers uniform.
Junior Seau!
RB Glen Bonner.Bonner wore #21 for the Chargers in 1974 and 1975.
Two noteworthy players have sported number 68 for the San Diego Chargers: Defensive end Leroy Jones (1976-83) and Pro Bowl guard Kris Dielman (2003-11).
George Roberts
Over the years, several players have worn the number 12 for the San Diego Chargers. Notably, quarterback Dan Fouts, a Hall of Famer, wore the number during his illustrious career with the team. Other players include Drew Brees, who also had a successful tenure as quarterback before moving on to the New Orleans Saints, and more recently, punter Mike Scifres. Each of these players contributed significantly to the team's history while wearing the number 12.
Ryan Leaf.
Ryan Matthews
They wore their blue, home game uniforms on January 17th.
Currently it is worn by safety Paul Oliver. In the past, it has been worn by wide receiver Gary Garrison, cornerback Charles Dimry, and safety Glen Edwards (who played most of his career in Pittsburgh).
running back for the San Diego Chargers football team he now plays for the jets of the 2010 season He wore number 21 for the chrgers