Vick came out of the Eagles' 38-23 loss to the Dallas Cowboys in the second quarter on Sunday. After being evaluated on the sidelines, Vick was taken to the locker room for further tests and did not return to the game.
Reid also said on Monday that Vick was "a little foggy last night."
Vick had completed 6-of-9 passing attempts for 70 yards and a touchdown before he was knocked out of the game.
Rookie Nick Foles came in to replace Vick and finished the game 22-of-32 passing for 209 yards and one touchdown, but he did throw an interception that was returned for a touchdown.
The Eagles play on the road next week against the Washington Redskins, but there has been no word yet about Vick's status for that game.