CNN  — 

It’s been a turbulent fortnight for the NFL and its concussion protocols, with the league coming under intense scrutiny over the issue of players’ health.

The saga around Miami Dolphins quarterback Tua Tagovailoa, which ended in him being taken to the hospital after suffering a concussion in a scary looking incident, has raised a number of questions about the handling of head injuries.

An investigation is now underway into the handling of Tagovailoa’s apparent head injury, while the unaffiliated neurotrauma consultant who was involved in the quarterback’s first concussion evaluation is reportedly no longer working with the National Football League Players Association (NFLPA).

NFL Chief Medical Officer Dr. Allen Sills told CNN Chief Medical Correspondent Dr. Sanjay Gupta on Friday that “we will get this right.”

Tua Tagovailoa sits on the turf during the first half of the game against the Buffalo Bills.

Tagovailoa will miss the team’s next game against the New York Jets on Sunday.

“It’s too early to give a definite timeline,” Dolphins head coach Mike McDaniel said. “I can comfortably say he’ll be out for this game against the Jets. But anything beyond that, again we’re just focused on making sure he’s at optimal health and then crossing that bridge so it’s a little early for definitive timelines beyond that.”

McDaniel added that Tagovailoa was currently inside the team’s facility and has had “a couple good days.”

“He’s just trying to go through with the proper procedure and protocol so he’s feeling 100%,” McDaniel said. “I know he’s going to be diligent with it and if there’s obviously any things that are giving him issues in terms of lights and those things, we will shut that down.”

The beginning of the scrutiny

It all began on Sunday, September 25, in the Dolphins’ 21-19 win over the Buffalo Bills.

Tagovailoa was knocked out of the game briefly in the second quarter after a hit by Bills linebacker Matt Milano forced the back of the Dolphins QB’s helmet to hit the turf.

The 24-year-old quarterback got up stumbling and was taken to the locker room for a concussion check. Milano was flagged for a roughing the passer penalty.

The Dolphins initially announced Tagovailoa was questionable to return to the game with a head injury, but he came back out onto the field in the third quarter and finished the game throwing for 186 yards and a touchdown.

Tagovailoa told reporters after the game that he fell onto his back before his head hit the turf causing his back to lock up and the resulting stumble. He added that he was evaluated for a concussion but was ultimately cleared.

McDaniel, the Dolphins head coach, alluded to a back injury after the game, saying that Tagovailoa back got “bent” on an earlier play but the hit “loosened his back” causing his legs to get wobbly. McDaniel added that Tagovailoa told him that his back was like “Gumby” – a reference to the classic green animated character.

Then, just four days later, Tagovailoa took to the field as the Dolphins played the Cincinnati Bengals on Thursday Night Football.

Tagovailoa was sacked by Bengals defensive lineman Josh Tupou in the second quarter and laid motionless on the field for several minutes.

The entire Dolphins sideline 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.

Medical staff tend to Tagovailoa as he is carted off on a stretcher after an injury during the second quarter of the game against the Bengals.

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, who is 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.”

Tagovailoa was cleared to return to Miami after visiting the hospital, and McDaniel told reporters on Friday that his quarterback was in “good spirits.”

But Chris Nowinski, who is co-founder and CEO of the Concussion Legacy Foundation, has told the NFL it must “do better.”

“This is bigger than protocols,” tweeted Nowinski. “A concussion can change a life. For me, it’s personal. We can’t let any other children grow up without their fathers.” CNN has offered the NFL the right of reply to Nowinski’s tweet.

Minnesota Vikings wide receiver Adam Thielen said the league has a duty to “protect” quarterbacks when they’re hit on their head.

“Obviously, those definitely have to be called because we got to protect our quarterbacks in this league,” Thielen said when asked about hits to Vikings quarterback Kirk Cousins’ helmet. “They’re huge and very important to the success of this league and to these teams, having a good product on the field. Got to protect those guys.”

The NFL and the NFLPA released a joint statement saying that both sides agreed that updates to the protocols are required, in particular to “gross motor instability” incidents.

Sills told Gupta that the ongoing review includes the players, the NFL and the NFLPA, as well as trainers, physicians and independent experts.

“We’ll be very transparent and very open about what we learned from that and exactly what the sequence of events are,” added Sills.

Gupta noted on Sunday that Tagovailoa had trouble walking after his helmet hit the turf in the game against the Bills – a potential “no-go” sign, meaning a player should not and would not return to the field.

Tagovailoa warms up before the game against the Bills.

Sills said that such “gross motor instability” is a “no-go” sign if it’s determined to be from a neurological cause.

The Bills hit is still under review, he said, and “that’s very hard to judge from video alone.” Sills emphasized that the decision about whether a player can return to a game is never made by one person but rather a group of physicians, including an independent neurological expert.

On Sunday, two quarterbacks left games as a result of the concussion protocol: Tyrod Taylor of the New York Giants and the New England Patriots’ Brian Hoyer.

Baltimore Ravens head coach John Harbaugh has called the events “astonishing” while NFLPA president JC Tretter