The Dolphins QB appeared seriously hurt in a scary incident after he was slung down, hitting the back of his head on the ground, in a sack from Josh Tupou with 5:46 remaining in the second quarter.
Tagovailoa seemed immediately dazed and awkwardly raised his hands with his fingers extended in an apparent seizure while on the ground.
Medical staff attended to the 24-year-old who remained on his back on the ground with minimal movement for approximately 10 minutes before he was stretchered off the field. He was immediately taken by ambulance to a nearby hospital in Cincinnati.
The Dolphins confirmed he was out of the game with head and neck injuries and added: "Tagovailoa has been taken to a local hospital for further evaluation. He is conscious and has movement in all his extremities."
The incident comes after Tagovailoa took a heavy hit in last week's 21-19 win over the Buffalo Bills and stumbled to the ground in the aftermath, yet was cleared of concussion and permitted to play on.
Dolphins head coach Mike McDaniel had insisted that the proper concussion protocols were followed and that the QB was cleared by the team and the independent neurologist at half-time.
Tagovailoa had been listed as "questionable" for the Bengals game due to back and ankle problems which limited his ability to practice this week, rather than a head injury.