McCown wore a black glove on his throwing hand and made several strong throws before practice. After the workout, which was closed to the media, McCown chatted briefly with Kiffin and offensive coordinator Greg Knapp before heading into the locker room.
The Raiders aren't so much concerned with McCown's finger injury as they are with his sprained right foot.
"He pushed through it today and looked good on it," Kiffin said. "Obviously he had to take snaps today and stuff with the hand but as I said there is not an issue with the hand, it was the foot and to see him move around and really pushed him today to see how far he could go and he responded really well."
Kiffin indicated it was important that McCown practice Thursday if he had any chance of playing on Sunday. McCown didn't practice Wednesday and Culpepper took the majority of reps with the starting offense.
McCown was originally named Oakland's starter prior to last week's game against Detroit but his hold on the position was tenuous. Kiffin said Culpepper, who signed with the team July 31, had simply run out of time in trying to catch up with the rest of the offense in terms of knowing the playbook.
After the loss to the Lions, Kiffin also reiterated that McCown would remain the Raiders' starting quarterback, though he backed off slightly on Thursday.
"When I made that statement we did not know the extent of an injury," Kiffin said. "If there would have never been an injury at all, yes, Josh would have definitely been our starter this game. But you have to take everything into account and we will at that time."