Quarterback Tua Tagovailoa, who left the Sept. 12 game with another concussion, is being placed on injured reserve by the Miami Dolphins, NFL Network and ESPN reported Tuesday.

He will be required to miss at least the next four games, per league rules. With the Dolphins having a bye in Week 6, the earliest Tagovailoa could return to game action would be the Oct. 27 matchup with the Arizona Cardinals.

In anticipation of a prolonged absence for Tagovailoa, the Dolphins signed Tyler Huntley off the Baltimore Ravens’ practice squad Monday to back up Skylar Thompson at quarterback.

After the 26-year-old Tagovailoa suffered the third known concussion of his NFL career — which doesn’t count a concussion at Alabama and another suspected concussion in 2022 — there were calls, including from several former NFL players, for Tagovailoa to consider retiring. NFL Network reported Sunday that Tagovailoa has no plans to retire and had begun meeting with concussion specialists.

As expected, that wasn’t a topic Dolphins coach Mike McDaniel wanted to touch when he addressed reporters Monday.

“I’ll let Tua be the champion of his own career and speak on that,” McDaniel said. It was unclear when Tagovailoa would speak to the media next.

McDaniel also was asked Monday if Tagovailoa was exhibiting symptoms.

“He’s downstairs, smiling with teammates, working with medical staff diligently,” McDaniel said. “He’s doing well today. He’s feeling good. But what does that mean in terms of medical diagnosis? I don’t base my judgments off my interactions with him as much as hearing the end result of the medical examination.”

Tagovailoa suffered a concussion during the Sept. 12 loss to the Buffalo Bills. He scrambled for a first down on a fourth-and-4 play in the red zone, but instead of sliding, he collided with Buffalo safety Damar Hamlin, his head making contact with Hamlin’s arm.

Tagovailoa appeared to exhibit a fencing response, but rather than being carted off by ambulance, as he was during a similar sequence in 2022, he was able to leave the field under his own power.

Thompson, the only other quarterback on the Dolphins’ 53-man roster, finished out Thursday’s game. McDaniel said Thompson would be Miami’s starter for Week 3 against the Seattle Seahawks, with Huntley signed to back him up.

“He’s game has developed since he’s had a starting opportunity in this league. His teammates can feel his development and growth,” McDaniel said of Thompson.

Thompson played in seven games, starting two, in 2022 and did not see the field in 2023. He has thrown for 614 yards, one touchdown and three interceptions on a 57.1 completion percentage in his brief NFL career.

Huntley, 26, has started at least one game in each of the past three seasons for the Ravens, filling in for Lamar Jackson. In 20 career games (nine starts) since 2020, Huntley has amassed 1,957 passing yards, eight touchdowns, seven interceptions and a 64.6 completion percentage.