Heiskanen underwent successful knee surgery in New York on Tuesday and is being labeled month-to-month, Stars radio analyst Bruce LeVine reports.

EDGE Analysis

Heiskanen's injury is a brutal loss for a Dallas club that is jockeying for playoff positioning in the Central division. Heiskanen was injured Jan. 28 against the Golden Knights after a collision with Mark Stone and placed on injured reserve Friday. Given his timeline, it's unclear whether Heiskanen will be back in time before the conclusion of the regular season. While he's unavailable, Brendan Smith should receive more opportunities, and Thomas Harley will quarterback the No. 1 power-play unit.