"He didn't do everything because he's not starting," Oakland coach Lane Kiffin said, "but I think he could have done everything if he had to."
McCown has started the last two games for the Raiders but has put up tepid numbers while failing to halt Oakland's losing streak. Culpepper, who went 1-3 as Oakland's starter earlier this season, was promoted to starter earlier this week after McCown pulled up injured against the Bears.
With only rookie JaMarcus Russell and veteran Andrew Walter left, the Raiders could head into Minnesota with a No. 2 quarterback who hasn't played at all this season. Russell has been trying to play catch-up with the offense ever since missing all of training camp and the preseason, while Walter has been fourth on the depth chart and was on the trading block at one point.
Kiffin refused to say who his No. 2 quarterback would be.
"I don't know yet for sure," Kiffin said. "I have to see how (McCown) responds tomorrow."
Russell spent most of Thursday taking reps with the scout team but Kiffin did not rule him out. He also said that playing in Minnesota, where the Vikings crowd can be extremely loud in the Metrodome, would not affect his decision on whether to use the rookie QB.
"Not if you're just going to play him for just a certain number of reps and at a certain point of a game," Kiffin said. "He's looking better. He gets more comfortable, gets more confidence in himself and the people around him."