Karlsson is considered week-to-week with an upper-body injury, so he will be out of the lineup for the foreseeable future.
It is unclear when or how Karlsson sustained the injury, though the Knights recalled Nicolas Roy from the AHL yesterday.
Ironically, the Knights will play the first game in franchise history tonight without Karlsson and without Gerard Gallant, who was relieved of his coaching duties yesterday.
Karlsson is the only player to have suited up for every Knights game over the last three seasons; tonight snaps a 234-game streak going back to his time in Columbus.
The latest setback for the Knights comes in the midst of a four-game losing streak and one day after the shocking coaching change.
Peter DeBoer is set to make his Knights coaching debut tonight, but he will have to do so without Vegas’ first-line center.
Karlsson has 10 goals and 34 points in 49 games this season.