Colorado Avalanche forward Mikko Rantanen has been ruled week-to-week with a lower-body injury after exiting the team's Monday night loss to the St. Louis Blues.

Head coach Jared Bednar said he expects the team to know more on the severity of Rantanen's injury by early next week.

"He is one of the best players in the NHL. When you lose one of the best players in the NHL its tough," teammate Nathan MacKinnon said of Rantanen. "We're not going to replace him, but he got hurt last year and we found a way to get some wins. Hopefully we can weather the storm until he gets back. Mikko is a freak, he will be back I'm sure sooner than later and like I said we need guys to step up, including myself."

The injury occurred in the second period against the Blues, when Rantanen was skating back into the neutral zone and his left skate caught the ice, having his ankle turn sideways.

The 22-year-old needed help getting down the tunnel to the dressing room.

The Finnish forward has 11 points in eight games to open the 2019-20 season. 

He enters this season fresh off signing a six-year $55.5 million contract as a restricted free agent this summer.