Karlsson (undisclosed) was placed on injured reserve Tuesday, according to Tim Hiebert of The Hockey News.
Karlsson's status for Opening Night on Wednesday against Colorado remains unclear. He missed another practice Monday after suffering an injury during training camp. He registered 30 goals and 60 points in 70 games during the 2023-24 regular season. If Karlsson sits out Wednesday's contest, Nicolas Roy could center the third line.