Per Saad Yousuf of The Athletic, Heiskanen (lower body) is considered week-to-week.
The good news is that Heiskanen will not require surgery and the injury is not season ending. Heiskanen was injured Thursday versus Colorado. He had four assists in his last four games, giving him 27 points in 37 games this season. He will be replaced by Thomas Harley on the first power play while Esa Lindell could see some time on the second unit.