Mason Foster has been ruled out of the Tampa Bay Buccaneers' game against the Detroit Lions this weekend with a concussion.
The linebacker will miss a game for the first time in his four-season career, as he is still suffering with symptoms of the head injury.
Head coach Greg Schiano told reporters: "He still has symptoms. We did it last week with Da'Qaun [Bowers], if there's any doubt, they're not going to play. It's not an ankle or a wrist or something, it's his brain and that's what's the best thing to do.
"By taking all the information [from the] doctors, what the player is reporting, it's a serious thing, these head injuries. I don't know the length, I don't know if he'll be ready next week or for weeks to come, I don't know that. We'll just have to play it by ear."
Foster has 55 tackles, two sacks, a forced fumble and two interceptions so far this season.