Chip Kelly has confirmed that Michael Vick will miss at least one game after reinjuring his hamstring at the weekend.
The Philadelphia Eagles quarterback initially picked up the knock at the start of the month, before returning against the New York Giants yesterday.
The team's head coach told reporters: "Mike didn't seem like he was going to be ready this week. He felt like, the first time, that he was going to be back after the Giants game.
"This is the first time I've talked to him where he thought he may be out. We'll see after we sit down and visit, after we get the final [MRI] results. I wish I knew a lot more than I do know."
Vick, who has described the injury as the worst that he has had, was forced to leave the game during the second quarter, while backup Nick Foles missed the contest with a concussion.
The Eagles play the Oakland Raiders on Sunday.
