I mean, he is another guy back there, but he is nothing special. Basically all he has done is throw a swing pass and run the ball, everything else has been pretty bad. I don't really see how Prescott couldn't at least pull that off. We will be in trouble if Russell gets hurt. Nothing could have prevented that unless Prescott is amazing, which I doubt because our backups are always supposed to be so good.
Favre is depth, but not quality depth, and I don't see why anyone else that has played Quarterback in high school would be any worse than him.