one of the tasks of a backup is to know your role. Black or White, you don't see many guys go from STAR to backup, because their ego can't take it. You need a backup who gets ready to play, but is comfortable with the fact that he likely won't, and isn't gonna raise a stink about how he should be the starter.

Mike Vick is prolly the highest profile backup in recent memory, and he only was willing to do that because he had been in prison, and that was his only way back into the league.

Guys who have been at the STAR level and gone on to have multiple seasons as a backup are rare.