SAN JOSE -- Marc-Edouard Vlasic made an early exit Saturday night, and there's no guarantee he'll be back for Game 6.

The team's top defenseman left the ice with an undisclosed injury at 14:09 of the first period after Los Angeles Kings center Jarret Stoll checked him into boards.

Sharks coach Todd McLellan was in no mood to elaborate on Vlasic's status after a 3-0 defeat in Game 5 at SAP Center.

"There is an obvious answer: He didn't return after the blow he took the head from Stoll,'' McLellan said coolly. "He has an upper-body injury. Call it that."

When asked if Vlasic would be OK to play Monday in Los Angeles, McLellan said simply: "I don't know."

On the fateful play, Stoll's right knee appeared to hit hard into the back of Vlasic's left leg. After that, Stoll's right forearm connects with the back of the defenseman's head.

McLellan was unfazed that the hit merited only a two-minute minor for roughing.

"The (officials) have a tough job,'' the coach said. "They can't determine extent of the injury on the spot. I don't hold them accountable."

Vlasic's absence left a big void in the defense Saturday, as the Kings outshot the Sharks 41-30.

The extra work for the five healthy defensemen clearly took its toll.

"Obviously, playing with five 'D' is not something we're used to,'' defenseman Dan Boyle said. "And when you're down 3-0, that's when it gets really difficult. Things like pushing the puck definitely gets a little difficult."

Vlasic's absence is a rarity. This was his 81st playoff game, extending his Sharks record for most postseason games by a defenseman.

He also had a consecutive games streak reach 217 games before he sat out April 11 against the Colorado Avalanche. The streak ended not because of an injury, but because the Sharks wanted him fresh for the playoffs.

Now, the question is whether he'll have to sit out a crucial postseason game.

Sharks center Joe Thornton said that the other defensemen did what they could.

"I thought that the five we had really stepped up,'' he said.

But the Sharks clearly lacked a dominant possession player, someone who could clear the zone during the Kings' many onslaughts. That's Vlasic's specialty, and he did it well enough to merit consideration for this year's Norris Trophy.

He was also off to a strong start in the playoffs. He was named first star after a Game 1 win and had an assist and a plus-2 rating in Game 3.

Follow Daniel Brown on Twitter at twitter.com/mercbrownie.