Briere was skating through the Nashville zone without the puck when he was hit from the blindside by Predators forward Eric Nystrom at 2:53 of the second period.
"I looked at the replay to see what happened," Nystrom said. "We were both looking, looking, looking [at the puck], and the next thing I know we just turned right into each other. I hate when that stuff happens, especially when somebody gets hurt, but I wasn't even looking at him or trying to run into him. We just collided."
Briere remained on the ice for a few minutes before retreating to the dressing room.
"I think it was an accident," Canadiens coach Michel Therrien said. "Two players ran into each other, I don't think the Nashville player was targeting the head. In my opinion it was an accident."
Briere has a history with concussions, missing 10 games last season with the Philadelphia Flyers when he sustained one in March. He missed six games during the 2011-12 season with a concussion sustained in January 2012.
Canadiens forward Brandon Prust was knocked out of the game midway through the third period when he fell awkwardly into the end boards in the Nashville zone. The Canadiens announced he has an upper-body injury and would be re-evaluated Sunday.