He is one of four starters to not be at the open portion of practice, joining linebacker Ashlee Palmer (ankle), right tackle Jason Fox (groin) and wide receiver Patrick Edwards (ankle). Safety Don Carey (hamstring), a special teams player, was also not at practice.
Safety Louis Delmas, who missed Wednesday's practice, returned Thursday. Also, defensive tackle Nick Fairley (shoulder) was at practice working in some drills. Left guard Rob Sims, who was listed as limited on Wednesday's injury report, practiced as well.
Palmer missed his second straight Thursday. He played last Sunday.
If Edwards can't play, look for more of Kris Durham and perhaps the season debut of Ryan Broyles. Corey Hilliard would continue to replace Fox. If Bush can't play, expect more of Joique Bell and perhaps rookie Theo Riddick.