CNN
 — 

Miami quarterback Tua Tagovailoa is in the NFL’s concussion protocol, Dolphins head coach Mike McDaniel said at a Monday news conference.

The announcement comes a day after Tagovailoa played the entire game as the Dolphins lost to the Green Bay Packers. It is the second time this season the 24-year-old quarterback has landed in the concussion protocol.

It also comes several months after he was in the spotlight for apparent head injuries and the league and the players’ union agreed to update the protocol – the NFL’s policies for assessing and caring for players who sustain a concussion.

Daniel said Monday afternoon that he had only found out “a couple hours ago” that Tagovailoa displayed concussion symptoms and had been placed in the league’s protocol by medical staff. He could not pinpoint a moment in Sunday’s game where Tagovailoa might have been injured.

It is unclear if Tagovailoa will be available to play this week against the New England Patriots, the coach said.

“I care very deeply about each and every player,” McDaniel said. “I take that seriously, so I just want him to get healthy and have peace of mind in that regard. That’s first and foremost, and then whatever the circumstances are after, you deal with after. It’s about the human being and making sure he’s squared away.”

Tagovailoa also was diagnosed with a concussion on September 29 after being sacked in a game against the Cincinnati Bengals. Tagovailoa lay motionless on the field for several minutes before he was placed on a backboard and stretcher. He missed the team’s next two games.

That concussion came several days after Tagovailoa suffered an apparent head injury and was later allowed to continue playing in a game against the Buffalo Bills on September 25.

A concussion is a brain injury that happens after a hit to the head causes the organ to move back and forth inside the skull. But even after the brain itself stops shaking, there can be changes to the organ.

In October, Tagovailoa said he didn’t remember being taken off the field during the September 29 game.

“Getting carted off – I don’t remember that,” he said. “But I do remember the things that were going on when I was in the ambulance and then when I arrived at the hospital.”

He called the process of going through the protocol stressful.

“But all of it is done for player safety and I’m glad that I got to go through those things to understand more of the deals of concussions, and you know, the effects, long-term, short-term, things like that. I thought it was great I was able to go through that process and get cleared,” Tagovailoa said at the time.

The Dolphins occupy the seventh and final playoff spot in the AFC, one game ahead of the Patriots. The Dolphins have two weeks left in their regular season.