Pryor was knocked out of Monday night's 37-21 loss at Denver in the fourth quarter after a hard hit to the helmet by Wesley Woodyard. He was replaced by Matt Flynn.
Pryor will not be able to practice until he goes through the league-mandated concussion protocol. That means the Raiders (1-2) will have to prepare for Sunday's game against Washington (0-3) with the possibility that either Pryor or Flynn could start.
"We'll look at how he's doing tomorrow," coach Dennis Allen said Tuesday. "We'll see whether he's able to go or not. Then we'll see as the week goes on and make a determination on what we can do."
Allen said the team will have to make game plans for both the mobile Pryor and the more stationary Flynn to start. When Pryor beat out Flynn for the starting job, the Raiders tweaked their offense to take advantage of Pryor's mobility.
That has paid off so far with Pryor leading the team with 198 yards rushing through three games.
"It's a little bit of a challenge," Allen said. "But that's where we're at and that's what we've got to get ready to do. So, we've got to have a game plan if Terrelle's able to go that he can go in and execute and give us a chance to win. If not, we've got to have something in there that gives Matt Flynn a chance to have success."
The players had the day off Tuesday and Pryor is not allowed to talk to the media until he clears his concussion protocol. But he did send out a tweet earlier in the day apologizing to Raiders fans for the loss.
"I don't remember much! Good hit by whoever it was. I heard our team fought well. We will be back!" Pryor wrote.
Pryor added that he felt great and was ready to go but that will ultimately be determined by the doctors.
Flynn had been expected to start after Oakland gave up two draft picks to acquire him from Seattle in April and gave him $6.5 million in guaranteed money. But Flynn struggled in the preseason as he dealt with a sore right elbow and was beaten out by Pryor for the starting job.
Pryor has played fairly well in his three starts this season, completing 65.4 percent of his passes for 624 yards with two touchdowns, two interceptions and a passer rating of 86.7.
Despite the lopsided loss to Denver on Monday, Pryor had his best game as a passer in his brief career, going 19 for 28 for 281 yards and a touchdown in his second straight turnover-free game.
His night ended early when he got hit running a quarterback draw with Oakland trailing by 23 points. Woodyard had a helmet-to-helmet hit on Pryor but it did not appear to be illegal because it came when Pryor was running the ball between the tackles.
Pryor remained in the game for two plays before medical staff checked him out and decided to take him back to the locker room to determine whether he had a concussion.
Allen said he had not had second thoughts about running his quarterback late in a lopsided game and believed the team handled the scenario properly even though Pryor remained in the game briefly after the hit. There was a replay review after the hit and Allen saw no issues with Pryor as they discussed the next play.
"He didn't show any signs of any concussion or anything like that," Allen said. "We put him back in the game and then when he came over to the sideline that's when our medical people took a look at him and decided we needed to send him into the locker room for further evaluation. Football is a tough sport and there's going to be collisions and you try to do everything you can to make sure that you're taking into account player safety and I think our medical people followed the protocol that's set forth by the NFL. They followed it exactly how it's supposed to be followed. When we determined he had a concussion we got him out of the game."
NOTES: CB Tracy Porter had a concussion and his status is unknown for this week. The Raiders are already down one starter in the secondary with S Tyvon Branch out with an ankle injury. ... Backup FB Jamize Olawale had an MRI on his injured ankle.