The Boston Bruins, already with four defensemen sidelined with injuries, lost captain Zdeno Chara to a lower-body injury in the first period of Wednesday night's game in Colorado.
The team was already without defensive stalwarts Charlie McAvoy (concussion), Kevan Miller (broken hand) and Brandon Carlo (upper body), as well as rookie Urho Vaakanainen, who sustained a concussion last month after being called up to fill in.
Chara will be re-examined Thursday, Bruins coach Bruce Cassidy said after the 6-3 loss to the Avalanche.
"It seems like we're losing a guy every game," goaltender Jaroslav Halak said.