[jdc65]

I believe that Campbell told Shanahan that he wants to look on his own for an opportunity elsewhere, and he would rather stay away from voluntary workouts until he figures out his next move. Clearly Shanahan would trade him for a quality pick, but that seems unlikely to me. I don't consider a 4th a quality pick myself, but we'll see.
I think Campbell is the best back-up the team can get, and will keep him pending a 'good' offer.