The Bruins were missing defensemen Charlie McAvoy and Kevan Miller, who flew back to Boston earlier in the day, and forward David Backes, who was a late scratch. Cassidy said McAvoy wasn't feeling well, and Miller blocked a shot with his hand against the Edmonton Oilers on Thursday. "Morning skate, [Backes] gave it a go, didn't feel 100 percent so we exercised caution there," Cassidy said. Rookie defenseman Urho Vaakanainen, 19, made his NHL debut after being called up from Providence of the American Hockey League on an emergency basis. He had one shot and was minus-1 in 12:26. … Canucks rookie center Elias Pettersson, who leads the team with eight points (five goals, three assists) in five games, missed his third straight game with a concussion but skated Saturday morning for the first time since being injured against the Florida Panthers on Oct. 13.