Coach Dale Hunter said Wednesday that Backstrom "seems fine, but he's still got to be evaluated."
Backstrom was elbowed by Rene Bourque in the third period of Tuesday's 3-1 Capitals victory. Bourque received a minor penalty, and Backstrom was able to skate two more shifts before leaving the game for good.
Bourque had a disciplinary hearing Wednesday morning with NHL officials. The hearing was conducted via phone, not in person, meaning that under the terms of the collective bargaining agreement, any suspension will not be more than five games.
"The puck isn't even close," Capitals center Marcus Johansson said of the hit after the game. "And it's very, very unnecessary."
"Did it look really bad? Was he hurt? I didn't even know if I clipped him," Bourque said. "I didn't even know if I hit him in the head."
The Capitals don't play again until they open a road trip Saturday at San Jose.
If Backstrom has a concussion and is out for an extended time, it would be major setback for the Capitals, who have started to play better recently. Backstrom leads the team with 42 points.
Information from ESPN.com NHL reporter Pierre LeBrun and The Associated Press was used in this report.