LOS ANGELES – If the Chicago Blackhawks are going to end the Los Angeles Kings’ perfect postseason on home ice in Game 4 of the Western Conference finals, they’ll have to do it without their top defenseman.

Duncan Keith will sit out Thursday under a one-game suspension for high-sticking Los Angeles’ Jeff Carter in the second period of the Kings’ 3-1 victory in Game 3, opening a 20-stitch gash on the star forward’s face and cracking three of his teeth.

Chicago has a 2-1 series lead and could take control with a win in Game 4, but the uncertainty of Keith’s fate hung over both teams’ practices Wednesday. Keith is enormously important to the powerful Blackhawks, leading the club in ice time and ranking third in playoff scoring with 10 points.

Sheldon Brookbank, the likely candidate to take Keith’s place in the Blackhawks’ lineup, hasn’t played in the postseason.

“It’s been our strength pretty much all season, our depth on our blue line,” Chicago defenseman Niklas Hjalmarsson said before the suspension was announced. “So whatever happens with that, I think we’re going to be all right.”

Keith, whose ungloved hand was nearly slashed by Carter an instant earlier, got a double minor penalty for his high stick, but was allowed to stay in Game 3. Keith had a hearing with the NHL Wednesday, but spent the day waiting for a decision.

Keith is classified by the NHL as a repeat offender — a factor in suspension decisions — after elbowing Vancouver’s Daniel Sedin in the head late last season, sidelining Sedin well into the playoffs.

Keith attempted to apologize to Carter on the ice, claiming the high stick was an accident. The Kings’ top goal-scorer shrugged off the apology.

“There’s bigger things to worry about right now,” Carter said, shrugging off his broken teeth with a hockey player’s nonchalance. “We’re in a fight here, down two games to one. I don’t think that’s on our minds.”

Keith is averaging nearly 25 minutes per game in the postseason, nearly four minutes more than any other Blackhawk.