Petty (knee) wasn't cleared to play in Thursday's preseason game against the Bills, Rich Cimini of ESPN.com reports.
Petty, who is nursing a minor knee sprain, vowed to be healthy by the start of the regular season. Regardless of whether he heals up or not, Petty will enter Week 1 as nothing more than the No. 2 or 3 quarterback on the depth chart and thus has little value in the fantasy realm.