After spending the majority of his first North American campaign in the AHL, Mikko Rantanen was expected to be a key contributor for the Colorado Avalanche in the upcoming season. If that is still to be the case, it might not be right away.

On Sunday, the Avalanche announced that Rantanen has an ankle injury, and is expected to miss 2-4 weeks. The 19-year-old injured his ankle during the third period of Saturday’s 4-1 win over the San Jose Sharks’ prospects, leaving the contest afterwards. Rantanen had an assist in the game on a pinpoint pass to A.J. Greer.

Rantanen went scoreless in nine games with the Avalanche last season, finishing the campaign with a minus-7 rating. He led the AHL’s San Antonio Rampage in scoring however, accumulating 24 goals and 60 points in 52 games.

The Avalanche’s first-round selection (10th overall) in the 2015 NHL Entry Draft, Rantanen was widely expected to make the Colorado opening night roster. Though that could still be feasible depending on how quickly he recovers, his absence could open the door for another prospect, such as J.T. Compher or A.J. Greer.