Gallagher has been sidelined since Nov. 22, when he blocked a shot and broke two fingers on his left hand.
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Since sustaining the injury, the forward has repeatedly stated that returning in time to play outdoors versus the Boston Bruins in Friday’s Winter Classic was his goal. Gallagher practised at Gillette Stadium in Foxborough, Mass., alongside the rest of his teammates Thursday.
"It’s cool to bring in your family and friends and get an opportunity to be at a venue like this," Gallagher said.
"I wouldn’t come back if I didn’t feel like I could help the team. I didn’t want to come back for selfish reasons. The doctors helped me to come back and play, and now hopefully I can contribute."
Puck drop for the Winter Classic is slated for 1 p.m. ET.
Mike Condon will start in goal for the Canadiens. Tuukka Rask gets the nod for the Bruins.