Add ankle and back injuries to the maladies that threaten Tua Tagovailoa's availability for the Miami Dolphins on a short week.

Head coach Mike McDaniel said Tagovailoa was experiencing soreness in line with usual aches and pains the day after a game. But Tagovailoa had medical testing on multiple parts of his body, including his ankle.

That's in addition to the NFLPA pushing for a probe of how -- or why -- Tagovailoa was permitted to return Sunday after being checked for a head injury.

"He got to show a hunger and yearning to be with his brothers. All of the guys, whether they say it or not, it's something that sits with you," McDaniel said Monday.

Tagovailoa left the game against the visiting Buffalo Bills with 2:19 left in the second quarter. Bills linebacker Matt Milano shoved him to the ground for a roughing-the-passer penalty, and the back of Tagovailoa's head hit the turf. He was wobbly and stumbled to the ground while running off under his own power.

Tagovailoa ended up returning for the Dolphins' first possession of the third quarter.

After the game, the Alabama product said he hurt his back on a quarterback sneak earlier in the game.

"But for the most part, I'm good," Tagovailoa said. "Passed whatever concussion protocol they had."

Tagovailoa was able to stay in for the rest of the game. The Dolphins held off the Bills 21-19 to move to 3-0 and into sole possession of first place in the AFC East.

As part of the collective bargaining agreement, "the NFLPA, the NFL Management Council or any player involved in an alleged failure by a club employee or other member of a club's medical staff to follow any of the mandatory steps required by the NFL's Concussion Checklist shall each have the right (independently or collectively) to bring forward a complaint about such alleged failure to the Representatives, which complaint shall be submitted in writing."

McDaniel said the Dolphins would wait for results of testing to determine a plan for Tagovailoa this week. The Dolphins visit the Cincinnati Bengals on Thursday, a challenging turnaround with a healthy quarterback. McDaniel said he's not banking on any players who are hurt but knows there is time for the plot to change.

"I don't assume anything (regarding Tagovailoa's availability)," he said. "It wasn't out of the extreme norm of bumps and bruises after a game. As far as me being able to access my crystal ball, it's broke right now."

Teddy Bridgewater is the Dolphins' No. 2 quarterback and would start if Tagovailoa cannot play at Cincinnati.