Denver Nuggets forward Vlatko Cancar suffered a torn ACL in his left knee while playing for Slovenia in a World Cup preparation game Friday, sources confirmed to ESPN.

Cancar was injured when he landed after a transition dunk in traffic during the loss to Greece. He had to be helped off the floor, and an MRI confirmed that he suffered the ACL injury that could sideline him for all of next season.

Cancar, 26, averaged 5.0 points and 2.1 rebounds per game as a reserve for the NBA champion Nuggets last season. He had a chance to earn a more significant role with the departures of key bench players Bruce Brown and Jeff Green.

Cancar's injury leaves Dallas Mavericks superstar Luka Doncic as the lone active NBA player who will play for Slovenia during the World Cup.

The Denver Post first reported Cancar's injury.