"I felt the same feeling that I had the first time (he hurt the hamstring on Oct. 6)," Vick said. "I don't think it's as bad, but it did pop again. ... I've never had a hamstring injury this bad."
Rookie Matt Barkley replaced Vick but struggled against the Giants, committing two turnovers in Philadelphia's 15-7 loss.
Vick said he will have an MRI on the hamstring Monday. His availability for next Sunday's game against the Oakland Raiders is unknown.
But when Nick Foles was knocked out of the Dallas game with a concussion, Vick was determined to return for Sunday's rematch with the Giants.
"Once Nick got hurt last week, I just made up my mind that I was going to try to get out there," Vick said. "I was going to try to rehab as hard as I could all week and try to put myself in a position where I could get back behind the center and help our team win."
Vick didn't look good from the beginning of Sunday's game. He threw an interception on the Eagles' first possession and fumbled while being sacked to start off their second drive.
Vick reinjured the hamstring on the third drive, raising the question of whether he should have tried to play at all.
"I really can't say if I should have or shouldn't have played," Vick said. "I felt good going in. I felt like I did everything that I was supposed to do to reassure myself that I could go out and play.
"There's just nothing like actually being in the moment and having to move and having to react. I tested it plenty of times, but there's no simulation for guys coming at you, going to hit you."
Foles is following the NFL concussion protocol and has not been cleared to practice yet, according to coach Chip Kelly. When he is cleared, Foles will have to see an independent neurologist before he can return to the practice field.
Barkley could be the starter in Oakland next Sunday. The only other quarterback with the team is G.J. Kinne, who was signed to the practice squad last week.
Tight end James Casey was the Eagles' emergency third quarterback.
Barkley completed 17-of-26 passes for 158 yards with one interception Sunday. The rookie also lost a fumble as the Eagles' offense failed to score a point.