Charlie McAvoy scored a power-play goal with 45 seconds left in the third period, lifting the Boston Bruins to a 4-3 win over the Washington Capitals on Thursday night.

But the win might have been costly for Boston, which lost winger Brad Marchand to an apparent right shoulder injury in the second period when he was hit from behind into the boards by Garnet Hathaway — a “cheap” play that left the Bruins angry postgame.

“The [Marchand] one I didn’t like at all. … hit a guy in the numbers in a vulnerable spot,” Bruins coach Bruce Cassidy told reporters. “I’ve seen that from that player in the past, so I didn’t like that one at all. The league may or may not look at it. When it comes to [Marchand], sometimes they kind of move on. But in this particular case, seems like a vulnerable spot, against the boards, back high.

“But at the end of the day, we were able to overcome it. … Hopefully [Marchand] is OK. Tough job for the officials to call those quickly like that, but that one I didn’t particularly like.”

Boston also lost Anton Blidh in the first period to injury. The left winger needed a few minutes and a hand from an athletic trainer to get back on his skates after getting leveled on a hit by Tom Wilson with 4:33 left in the opening frame.

Cassidy said he had no problem with the hit from Wilson, who has a reputation for dangerous plays.

“On the Blidh one, he came into the middle of the ice and saw him at the last minute,” the coach said. “Wilson hits hard. We’ve seen that. Some clean, others not clean. I didn’t mind that.

“I thought he went for the chest. I thought he kept his elbows down. From my vantage point I didn’t see anything other than a hard hit.”

Both Marchand and Blidh will be reevaluated Friday, per Cassidy.

Information from The Associated Press was used in this report.