Pryor suffered a concussion during the fourth period of last Monday's 37-21 loss to Denver.
Backup quarterback Matt Flynn took the majority of snaps in Thursday's practice. Pryor must pass a number of NFL-mandated medical tests before he can take part in a game.
"There are still some hurdles he has to clear," Oakland Coach Dennis Allen said Thursday. "I hope we have a definitive answer sooner rather than later. When the doctors clear him for full participation, that's when we'll know whether he can play in the game or not."