"There's still a lot of swelling, the evaluation will continue but we know he'll be out at least a month. We'll know more in the near future," Sharks general manager Doug Wilson told ESPN.com Saturday.
Hertl was injured in a knee-on-knee collision with Los Angeles Kings captain Dustin Brown in Thursday's game. Brown was given a five-minute major for kneeing and thrown out of the game. The NHL decided the play did not warrant any supplemental discipline.
Entering Saturday's games, Hertl, 20, had a five-point lead atop the NHL rookie points race with 25 points (15-10) in 35 games. His injury could potentially hurt his chances to play in the Olympics for his native Czech Republic.