Even though he was in uniform as the emergency third quarterback Sunday against the Packers, his injured knee underwent a new MRI that will be examined Monday by Dr. James Andrews, according to sources.
Stafford suffered a subluxation of his right knee against the Bears two weeks ago and did not play last Sunday. On Wednesday, he returned to practice, only to have the knee suffer more swelling, which prompted the team's medical staff to order a new MRI on the rookie quarterback.
The MRI result has been forwarded to Andrews, a noted orthopedic specialist, for exam.
Sources say the biggest concern is that Stafford's knee cap is loose enough to require surgery, which could jeopardize the rest of his season. However, the Lions hope and believe more rest Sunday and a bye week next Sunday will provide Stafford with the necessary healing.
Stafford, however, told reporters immediately after the Lions' 26-0 loss that he knew nothing about his tests being forwarded to Andrews for review.
Stafford also said that he's not worried that he might need surgery to repair the knee.
He missed four of five practices this week.
"I'm not going to discuss his prognosis or his status or anything else going forward," Lions coach Jim Schwartz said after the game. "He has a knee, he hasn't been able to play the last two weeks. He got to where he wasn't able to warm up today, but we'll see if we can get him back on the field next week and move forward."
Stafford was listed as Detroit's emergency quarterback against the Packers. Starting quarterback Daunte Culpepper hurt his right hamstring on a scramble on the Lions' first possession of the third quarter.
Culpepper wasn't hit on the play, but began limping just before he reached the sideline. He took one more snap before Drew Stanton relieved him. Culpepper wasn't having a good day even before the injury, going 6-of-14 for 48 yards, an interception and two sacks.
Schwartz said after the game if Stanton also had been injured, Stafford wouldn't have come in and he would have elected to send Culpepper back in a shotgun formation to help limit his movements with the ailing hamstring.
"It never got to that point," Schwartz said.
Schwartz also declined to say whether Stafford might be available after Detroit's upcoming bye week when the Lions play the Rams on Nov. 1.
"I don't think I've ever put a timetable on when he's coming back," he said.
Chris Mortensen is a senior NFL analyst for ESPN. Information from The Associated Press contributed to this report.