What we know about the injury to Dolphins QB Tua Tagovailoa, and what's next

The joint concussion protocol of the NFL and NFL Players Association is facing serious questions Friday, one day after Miami Dolphins quarterback Tua Tagovailoa suffered a concussion and was briefly hospitalized during his team's 27-15 loss to the Cincinnati Bengals.

The injury occurred with 5 minutes, 15 seconds remaining in the second quarter at Paycor Stadium in Cincinnati. Tagovailoa's head hit the ground when he was sacked by Bengals defensive lineman Josh Tupou. Tagovailoa's arms grew rigid and his fingers curled in what appeared to be a "fencing response." Medical officials placed him on a stretcher and wheeled him to an ambulance.

The timing of the concussion ignited renewed scrutiny of the hit Tagovailoa took four days earlier in Miami when he was shoved to the ground by Buffalo Bills linebacker Matt Milano after throwing a pass. Tagovailoa grabbed his head and then stumbled after getting off the ground. The Dolphins originally labeled it a head injury but then later attributed the stumble to ankle and back injuries and allowed him to finish the game after he cleared an evaluation at halftime.

"We'll have all of those interviews," NFL chief medical officer Dr. Allen Sills told the NFL Network. "We'll review all of the video, we'll review all of the data. And the purpose of that review is to make sure that the concussion protocol was followed."

It was revealed Saturday that the unaffiliated neurotrauma consultant involved in clearing Tagovailoa was fired after it was learned he made "several mistakes," sources told ESPN Dolphins reporter Marcel Louis-Jacques. The NFL and its players' union said Saturday that modifications to the concussion protocol are needed.

Let's take a closer look at the issues surrounding Tagovailoa's condition, his next steps and what consequences -- if any -- will arise from an NFL/NFLPA investigation. -- Kevin Seifert

After the hit in the Bills game, what happened at halftime?

Tagovailoa's stumble after hitting his head on the ground suggested a display of gross motor instability -- which, according to the NFL's concussion protocol, required him to be taken directly to the locker room for evaluation. Dolphins coach Mike McDaniel said Tagovailoa insisted that a back injury he suffered earlier in the game was to blame for the stumble. The quarterback said Monday he had passed his evaluation for a concussion at halftime Sunday and was cleared to return to the game.

McDaniel said on Monday if "any red flag" popped up during the evaluation, Tagovailoa would not have played. He added that the team and an unaffiliated neurological consultant went "above and beyond" to the point where Tagovailoa was "annoyed" at the amount of questions he was asked about a potential head injury. The Dolphins initially reported him questionable to return with a head injury but later said it was ankle and back injuries. -- Marcel Louis-Jacques

Why would someone with gross motor instability be allowed to go back in a game?

After absorbing the initial hit in Week 3 against the Bills, Tagovailoa stumbled noticeably after getting up and had to be stabilized by teammates. The NFL concussion protocol refers to that type of stumble as "gross motor instability" and requires an evaluation to determine the cause.

That section of the protocol concludes: "If the team physician, in consultation with the sideline [unaffiliated neurotrauma consultant], determines the instability to be neurologically caused, the player is designated a 'No-Go' and may not return to play."

In Tagovailoa's case, the gross motor instability was attributed to a back injury and not a concussion. Because it was not "neurologically caused," according to the determination of the team and unaffiliated doctors, he was permitted to play under the terms of the protocol. -- Seifert

What was Tagovailoa's week like with the team leading into Thursday night's game?

Sills said Friday that Tagovailoa was checked for concussion symptoms every day this week, including Thursday. The Dolphins did not practice Monday, which is not unusual after a Sunday game. But they did release an estimated injury report as if they did practice, and Tagovailoa was listed as "DNP" -- did not participate -- because of back and ankle injuries. McDaniel said Tagovailoa was dealing with ankle and back soreness and would not commit to Tagovailoa's availability for Thursday's game. Tagovailoa had limited walk-throughs on Tuesday and Wednesday, and a league source told ESPN he made "good strides" from Tuesday to Wednesday. A final decision on his availability for Thursday's game was not made until Thursday morning. -- Louis-Jacques

When Tagovailoa was sacked on Thursday, it was reported he went into a fencing response. What is that?

The fencing response is an involuntary neurological response to a significant concussive event, in which the forearms become rigidly positioned outward for a brief period. The term originated from the sport of fencing (en garde) with the position of one arm flexed and the other extended. -- Stephania Bell

What's Tagovailoa's current situation, and what's happened since he was taken off the field?

Tagovailoa was treated at University of Cincinnati Hospital and was discharged before the Dolphins left the Cincinnati area for South Florida. Tagovailoa underwent testing, which showed no structural damage to the head or neck area, sources said. He was alert and had feeling in his extremities. He accompanied the Dolphins on the team plane and was in good spirits upon arrival, wearing a neck brace as a precaution. Tagovailoa is expected to undergo an MRI and receive a second opinion for his injuries. He's in the concussion protocol, which includes a five-step process for returning to the field. -- Jeremy Fowler

Tagovailoa is in the concussion protocol, so what's next?

Tagovailoa must proceed through a five-step process before returning to the field. This is what it looks like, paraphrasing from the return-to-play portion of the protocol:

Phase 1: Rest, and then limiting -- or avoiding -- physical and cognitive activities if they aggravate symptoms. Introduction of limited stretching and balancing work and moving to light aerobic exercise.

Phase 2: Gradual progress toward cardiovascular exercise, dynamic stretching and more balance work. Neurocognitive and balance testing can be administered. If the results are interpreted as back to baseline (pre-concussion) levels, Phase 2 is satisfied.

Phase 3: Increased cardio exercise to mimic sport-specific activity, along with supervised strength training. The player can practice with the team, doing sports-specific exercises, for 30 minutes or less.

Phase 4: The player can advance to noncontact football activities such as throwing, catching and running. Another round of neurocognitive and balance testing is administered to confirm results remain at baseline.

Phase 5: A club physician must clear the player for full football activity, including contact. Then, an independent neurological consultant (INC), assigned to the team by joint agreement between the NFL and NFLPA, must concur with the team physician that the concussion has resolved. At that point, the player is clear to play in his team's next game. -- Seifert

What can we expect from the NFL/NFLPA investigation?

As is its right under the protocol, the NFLPA requested a joint investigation into the Dolphins' handling of Tagovailoa's injury in the Bills game. The investigation began immediately. During a conference call three days later, NFL executive vice president Jeff Miller said that "every indication from our perspective" suggested that the Dolphins followed the protocols.

Miller estimated that the formal investigatory response would take one or two weeks.

Separately, NFLPA executive director DeMaurice Smith said in a statement released Thursday night to Amazon that the union would pursue "every legal option" as the investigation continues. Generally speaking, per the terms of the collective bargaining agreement, disputes between the league and union are settled via private arbitration.

On Friday, NFLPA president JC Tretter released a statement that said in part: "We are all outraged by what we have seen the last several days and scared for the safety of one of our brothers.

"Until we have an objective and validated method of diagnosing brain injury, we have to do everything possible, including amending protocols, to further reduce the potential of human error. A failure in medical judgment is a failure of the protocols when it comes to the wellbeing of our players." -- Seifert

Will the league revisit its concussion protocol?

The league and the players' union issued a joint statement Saturday that said they agree that "modifications to the concussion protocol are needed to enhance player safety."

"The NFL and the NFLPA agree that The NFLPA's Mackey-White Health & Safety Committee and the NFL's Head Neck and Spine Committee have already begun conversations around the use of the term 'Gross Motor Instability' and we anticipate changes to the protocol being made in the coming days based on what has been learned thus far in the review process," the joint statement said.

There is recent precedent for making in-season adjustments to the protocol. In 2017, Houston Texans quarterback Tom Savage was allowed to return to a game after displaying obvious concussion symptoms following a hit, including the fencing response and twitching fingers. He was diagnosed later with a concussion and did not finish the game.

After an investigation revealed no protocol violations had occurred, the league and union made a number of enhancements to existing rules to cover such instances. The additions mandated a player be permanently removed from a game if he shows any signs of impact seizure and also required referees who witnessed symptoms to inform team medical staff. Also, the league added an unaffiliated neurotrauma consultant to its game-day operations in New York to help supervise the process. -- Seifert

What can we expect from the Dolphins at quarterback if Tagovailoa does not play?

McDaniel said situations like these are why you sign a veteran like Teddy Bridgewater, who has a 33-30 record in 63 starts for the Minnesota Vikings, New Orleans Saints, Carolina Panthers and Denver Broncos over the past seven seasons. At this stage of his career, Bridgewater is more of a game manager. His highlights on Thursday night were a 7-yard touchdown pass to Chase Edmonds and a 64-yard pass to Tyreek Hill that put Miami deep in the red zone. He also threw a costly interception late in the fourth quarter. Skylar Thompson, a seventh-round pick out of Kansas State in the 2022 NFL draft, is Bridgewater's backup. -- Louis-Jacques