Brandon Weeden has been able to return to practise with the Cleveland Browns after sustaining a concussion at the weekend.
The rookie quarterback had to leave the game against the Pittsburgh Steelers early after being diagnosed with the head injury.
Weeden told the Browns' website: "It was mild. I never got knocked out. I was conscious the whole time, was just a little foggy.
"The league's taking this thing pretty seriously, so you've got to go through the mandated steps. I passed all those, so I'm ready to rock and roll.
"I wanted to do everything on my part to come back and play because I felt fine and ready to go, but it's not like it's an ankle or a hand. It's your brain. You've got to be smart."
The Browns play the Oakland Raiders on Sunday.