Jay Cutler has said that he suffered spasms after picking up a neck injury in the Chicago Bears' loss to the Minnesota Vikings.
The quarterback was unable to finish the game after his head was knocked violently backwards by defensive end Everson Griffen.
After the game, Cutler said: "It started stiffening up a little more as the game progressed, getting some spasms on the left side. So I just have to take it day by day."
Coach Lovie Smith added: "I thought he fought until the end. Of course we'd like to have a couple of those throws back. But Jay is gonna play like that always. We know what we're gonna get from him."
Cutler tried to continue playing after sustaining the injury, but eventually made way for backup Jason Campbell.
Cutler is not expected to miss next weekend's game against the Green Bay Packers.