Pryor first hurt the knee in the second half of a loss to Philadelphia on Nov. 3 and eventually left that game early. He said the knee got worse during the week of practice but he kept that information away from his coaches.
"I don't know that there was any type of disconnect or anything," coach Dennis Allen said. "We evaluated him during the week in practice and things seemed to be OK, but obviously, when you got in the game, it was pretty evident early in the game that he just didn't have that same explosiveness that he normally has."
Pryor only ran the ball five times for 19 yards and took four sacks as he struggled to get away from the Giants pass rushers on his bum knee.
The Raiders also could be without running back Darren McFadden this week. McFadden missed another practice as he recovers from a sore hamstring that forced him to miss last week's game.
Oakland did get some positive news on the injury front with right tackle Tony Pashos returning to practice for the first time since injuring his hip in the first half at Kansas City on Oct. 13 and left tackle Jared Veldheer practicing for the first time since tearing his left triceps in training camp.