Karlsson will return to the lineup Monday for the Golden Knights for Game 1 of their second-round series against the Anaheim Ducks, coach John Tortorella said.
Karlsson has missed the past six months with a lower-body injury. He last played Nov. 8 against Anaheim.
Before getting injured, Karlsson had four goals and three assists in 14 games during the regular season.
You can watch Game 1 on Sportsnet and Sportsnet+, starting at 9:30 p.m. ET / 6:30 p.m. PT.