Miami Dolphins offensive lineman Austin Jackson said he was "crushed" after seeing Tua Tagovailoa suffer another concussion in Thursday's loss to the Buffalo Bills.
The Dolphins were beaten 31-10 at Hard Rock Stadium, with Tagovailoa throwing for 145 yards, one touchdown and three interceptions before his third-quarter exit.
Tagovailoa collided with Bills defensive back Damar Hamlin on a fourth-down keeper before hitting the back of his head on the turf, staying down for two minutes as several Dolphins players crowded around him.
The quarterback was able to walk to the locker room but was swiftly ruled out as Skylar Thompson finished the game in his place, throwing for 80 yards and no scores.
Tagovailoa previously suffered two concussions during the 2022 season, when the NFL and NFLPA opened a joint investigation into how one of Tagovailoa's injuries was handled.
Asked about the mood in the Miami locker room after the game, Jackson said: "Crushed. I hate to see him like that. Even with his history already with that type of stuff, I hate to see it.
"I hate that it was him rushing out of the pocket. Wish I could get that back for all of us. I could have been better."
Tagovailoa previously missed two games after being concussed in a 2022 game versus the Cincinnati Bengals, then was shut down for the rest of the season when he sustained another concussion in a Christmas Day meeting with the Green Bay Packers.
Coach Mike McDaniel was in no mood to think about the timeline of his recovery after the game, saying: "Right now it is more about getting a proper procedural evaluation tomorrow and taking it one day at a time.
"The furthest thing from my mind is what the timeline is. We just need to evaluate him and I just worry about my team-mate.
"We'll get more information tomorrow and then take it day by day from there."
McDaniel added Tagovailoa's past head injuries will not inform the way Miami handle his latest blow, saying: "I think it's important to approach each and every situation with the mindset of, 'we're going to handle this particular situation with this particular player'.
"Every situation is unique. I am not worried about anything that's out of my hands, I'm just worried about the human being, and he'll drive the ship when we get the appropriate information. But it's day-by-day health, particularly with concussions."