(CNN) Miami Dolphins quarterback Tua Tagovailoa is "in good spirits" Friday after receiving a concussion during Thursday night's game, head coach Mike McDaniel told reporters.
The NFL and Dolphins are under scrutiny for the decision to allow Tagovailoa to play Thursday, after the quarterback was injured in a game just last Sunday. McDaniel said his focus right now is on Tagovailoa's health, and that he is not thinking about a timetable for his return to the field.
"(This) is somebody I've grown very, very close to," McDaniel said. "When it comes to head injuries and concussions, with things that severe, the only thing I'm worried about is the person first."
The NFL is reviewing the decision to clear Tagovailoa for play, and will be "speaking with everyone involved," its chief medical doctor told CNN Friday.
"Any time we have a situation like this, we go back to do a thorough review with everything associated with the situation, and we go back to look at the video and the medical reports," Dr. Allan Sills told CNN's Chief Medical Correspondent Dr. Sanjay Gupta on Friday.
"The NFL, the NFL Players Association and the medical leadership is going to be speaking with everyone involved and that means the team athletic trainer, and the team physician, and the independent neuro expert, and the spotter in the booth, and the neuro operator in the booth, and the patient themselves -- and so all of that is under way."
Tagovailoa was sacked by Cincinnati Bengals defensive lineman Josh Tupou in the second quarter, and lay motionless on the field for several minutes. The entire Dolphins sidelines walked onto the field as he was placed on a backboard and stretcher. Bengals fans in attendance at Paycor Stadium in Cincinnati showed their respect as Tagovailoa was carted off the field.
Video showed Tagovailoa's forearms were flexed and his fingers contorted -- a sign that Gupta, a neurosurgeon, said is a "fencing response" and can be linked to a brain injury. Gupta asked Sills, also a neurosurgeon, how concerned he was after seeing that video.
"Well, of course, I am concerned just like you as a neurosurgeon, and anyone with a significant injury and neurologic signs like that," Sills said. "The immediate concern is ... making sure that the moment we do everything that we can to provide the most expert and timely care ... securing the airway, making sure that there is not a spine injury and so on and so forth.
"I am concerned about that injury and all of the injuries."
Sills noted that the NFL will be "reviewing carefully all of the steps that led to the sequence of events that you described."
"We will be transparent about the outcome of that," Sills said.
McDaniel said Tagovailoa had a MRI on Friday but only as precaution after the CT scans and X-rays which were taken after the quarterback was taken off the field on a stretcher. The results of the MRI have not been released.
The Dolphins said Tagovailoa was conscious after the injury and had movement in all his extremities. He was evaluated at a local hospital before he was released to travel back to Miami with the team Thursday.
McDaniel, a first-year NFL coach, was asked if he would have handled Tagovailoa's situation differently after the quarterback got an apparent head and neck injury during Sunday's game against the Buffalo Bills.
"He was evaluated (for a head injury) and cleared after several layers of medical professionals, who I don't pretend to be one," the coach said. "Those people, the collection of them, cleared him of any head injury whatsoever. He had a back and ankle issue.
"In terms of deciding to not play a guy on a Thursday night game, I'm concerned about his lower back and ankle and putting him in harm's way," McDaniel added. "I have 100% conviction in our process. ... I wouldn't have been able to live with myself if I prematurely put someone out there and put them in harm's way."
Tagovailoa was joking around and happy to be on the plane with his teammates during the trip home from Cincinnati after the loss, McDaniel said.
He sat next to his head coach and even started playing one of McDaniel's favorite comedic movies "MacGruber."