Tua Tagovailoa, the quarterback for the Miami Dolphins, appeared to sustain a head injury during Thursday night's game in Cincinnati.
Tagovailoa was carried off the field on a stretcher and taken to a nearby hospital.
Later, coach Mike McDaniel said the player had simply had a concussion, and the club declared that players would board a plane to return to Miami.
With 5:43 left in the first half, Tagovailoa was sacked by Cincinnati's Josh Tupou and swung to the ground viciously.
Tagovailoa's head and upper back landed hard on the turf, and his fingers spasmed strangely
For almost ten minutes, Tagovailoa lay on the field before being removed and transferred by ambulance to the University of Cincinnati Medical Center.
Tagovailoa suffered the injury four days after temporarily leaving Sunday's game against the Buffalo Bills and returning after passing the concussion protocol.
Tagovailoa was cognizant throughout the night and has full mobility of his extremities, according to the Dolphins.
Tagovailoa was scheduled to be released Thursday night and return to Miami with his teammates.
The Bengals defeated the Dolphins 27-15, handing them their first setback of the season.