What we know about Dolphins QB Tua Tagovailoa's concussion -- and what's next

MIAMI -- Dolphins quarterback Tua Tagovailoa suffered the third diagnosed concussion of his NFL career on Thursday night in a 31-10 loss to the Buffalo Bills.

Tagovailoa was ruled out of the game in the third quarter after a play in which he scrambled up the middle for a first down and lowered his shoulder to initiate contact with Bills safety Damar Hamlin. After Tagovailoa's helmet made hard contact with Hamlin's body, the quarterback immediately went into a fencing response, a term used to describe a person's arms going into an unnatural position.

Dolphins medical trainers attended to him for several minutes as players knelt around him. He was ultimately able to walk off the field and into the team's locker room under his own power.

The Dolphins have 10 days until their next game against the Seattle Seahawks but could rule out Tagovailoa, regardless of how he progresses through the league's concussion protocol. A stint on the injured reserve could be another possibility considering his injury history.

"Right now, [it] is more about getting a proper procedural evaluation and taking it one day at a time," Dolphins coach Mike McDaniel said after the game. "The furthest thing from my mind is what is the timeline. We just need to evaluate and just worry about my teammate. ... We'll get more information [Friday] and then take it day by day from there."

Here are four key questions following Tagovailoa's latest concussion.

Tagovailoa was a candidate to be selected as the top quarterback in the 2020 NFL draft during his final season at Alabama but suffered a hip dislocation and fracture of the posterior wall of his hip socket midway through the season. He was also diagnosed with a concussion and broken nose that year.

Tagovailoa recovered in time to play for the Dolphins as a rookie but missed five games during his first two seasons because of various minor injuries. In 2022, he was diagnosed with two concussions and took a third hit to his head that ultimately led to the NFL altering its concussion protocol.

He didn't miss a game during the 2023 season, however, and earned a four-year, $212.1 million contract extension in July.

Tagovailoa admitted to briefly considering retirement after conversations with his family. During an interview with "The Dan Le Batard Show" last month, he clarified that it was primarily his mother who asked him to reconsider his playing career.

Ultimately, he decided against it and spent the 2023 offseason bulking up and training in a jiujitsu breakfall program to learn how to fall without hitting his head on the ground.

The training seemed to help as he played in all of Miami's games last season, including a playoff loss to the Kansas City Chiefs. This offseason, Tagovailoa told CBS Sports he lost 14 pounds in an effort to be more mobile.

McDaniel said Tagovailoa will undergo thorough testing and evaluation before they decide how to proceed. The NFL's return-to-participation protocol is a five-step process that culminates in a team's physician concurring with an independent neurological consultant that a player can safely play again.

The first step of the protocol is rest and recovery "until his signs and symptoms and neurologic examination" return to "baseline status." The next step is light aerobic exercise, followed by continued aerobic exercise and introduction of strength training.

A player can return to football activities in the fourth step of the protocol, all of which are noncontact. The final step is full clearance, once the physician and neurological consultant agree the player is ready.

If Tagovailoa cannot play in next week's game against the Seahawks, third-year quarterback Skylar Thompson is in line to start. Thompson started three games as a rookie in 2022, including a playoff loss on the road at Buffalo.

The only other quarterback on the Dolphins' roster is Tim Boyle, who is signed to their practice squad. There are free agent options available should Miami decide to bring in another quarterback, notably the team's first-round pick in 2012, Ryan Tannehill.

McDaniel did not commit to the possibility of playing without Tagovailoa but expressed the "utmost confidence" in Thompson. It's unlikely Miami would immediately bring in another quarterback to start over Thompson, but it could add depth if Tagovailoa is forced to miss time.