From what I've researched, no one wore number 21 for the San Diego Chargers in 1998.
Byron Jerideau is number 68 on the San Diego Chargers.
Junior Seau!
RB Glen Bonner.Bonner wore #21 for the Chargers in 1974 and 1975.
Ryan Leaf.
George Roberts
Ryan Matthews
Most players never wore a chargers uniform.
Several players have worn the number 77 for the San Diego Chargers, notably including Hall of Fame offensive lineman Ron Mix, who played for the team from 1960 to 1969. Other players who wore this number include offensive tackle Ed White and defensive tackle Gary "Big Hands" Johnson. The number has been associated with strong offensive line play during its time with the Chargers.
The only two are Brad Arnsberg in 1986 and Dioner Navarro in 2004.
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
As far as I know there is nobody currently wearing the number 68 but Jaromir Jagr, Milan Jurcina, and Zigmund Palffy wore it.