Tua Tagovailoa was foolish for returning to the Bills game on Sunday after slamming his head on the turf ... so says famed neuropathologist Bennet Omalu -- who tells TMZ Sports the Dolphins quarterback put his life at risk by making the comeback.
Dr. Omalu -- who's the real-life inspiration for the famous Will Smith "Concussion" movie -- says that under no circumstances should Tagovailoa have come back into the contest in Miami after he was initially knocked out of it.
Omalu says he suspects Tagovailoa suffered a concussion based on everything he saw on the game's broadcast ... and he said the 24-year-old should have protected himself and his future and stayed on the sideline the rest of the day.
Full replay of the Tua (possible) concussion play. He got hit by Matt Milano and hit the turf with his head. pic.twitter.com/29dqNyJ45L
"I got up, and that's kind of why I stumbled," the signal-caller told reporters after Miami secured the 21-19 win over Buffalo. "My back kind of locked up on me. But for the most part, I'm good. Passed whatever concussion protocol they had."
The NFL Players Association has launched an investigation into the handling of the incident.