The incident occurred about midway through the final frame as Crosby skated into Bergeron, who was not carrying the puck at the time and fell backward and hit his head against the boards. Bergeron stayed down until the whistle blew and was assisted off the ice and back to the locker room.
No penalty was called on the play although Crosby was sent to the box for roughing about a minute later.
The 36-year-old Bergeron is third on the team in scoring with 35 points (12 goals and 23 assists) in 43 games this season, his 18th with the Bruins and second as captain.
"I don't know if the concussion [spotter] took him out the way he went into the boards. I wouldn't be surprised," said Cassidy after the game. "When you're down like that, that's typically what happens. I didn't speak to him, and he didn't come back to the bench. I went into the training room and he wasn't there. That's about all I've got for right now. Hopefully he is OK."
"I don't know, that happened quick," Cassidy said about the situation. "Honestly, lack of discipline, obviously, on Brad's part in that situation…I just watched the replay at the end, it looks like some words were exchanged. I don't know if there was an incident in the second period that precipitated it. I wasn't in the room, I don't know. Someone said that.
"Still, gotta have better discipline at the end of the day. Brad's a leader on the team and he needs to control his emotions in that situation."
Earlier in the game, Marchand hit the puck off of Jarry's stick as he was trying to give the puck to a Penguins fan in the crowd. Jarry appeared to say something to Marchand as both teams skated off the ice.
When asked about the incident with Marchand, the Penguins goaltender didn't make much of it.
“I think it was the heat of the moment. Everyone is battling out there, and he was just trying to get the puck to the net, and our team did a great job,” Jarry said.
Crosby scored the go-ahead goal, his 499th career tally, earlier in the game as the Penguins defeated the Bruins 4-2.