TORONTO – Center Alexander Wennberg sustained an upper-body injury Monday night, forcing him to leave the San Jose Sharks’ game against the Toronto Maple Leafs at Scotiabank Arena.

It wasn’t immediately clear what caused Wennberg’s injury, but he didn’t play the final 3:56 of the third period in a 3-1 loss to the Maple Leafs. The same issue also forced Wennberg to leave the Sharks’ bench briefly earlier in the period. He finished with 16:19 of ice time.

Sharks coach Ryan Warsofsky said postgame that he hadn’t received an update on Wennberg and didn’t know whether his ailment would keep him out of Tuesday’s game in Montreal against the Canadiens.

If Wennberg misses Tuesday’s game, his absence would no doubt ripple through the Sharks’ lineup.

Wennberg, the Sharks’ second-line center, entered Monday with three assists in eight games and is typically matched up against the opposing team’s top line, especially at home. He was also third among all Sharks forwards in average ice time (20:00) and led the team in faceoffs taken with 158, including 113 at even strength.

Recently, he’s formed an effective line with Mason Marchment and Tyler Toffoli. Marchment scored the Sharks’ only goal Monday, taking a pass from Toffoli behind the Leafs’ defense and beating goalie Sergei Bobrovsky in close for a 1-0 San Jose lead 13:54 into the first period.

“They’ve been pretty good actually,” Warsofsky said of the line. “Obviously, scored a big goal there. They’ve been doing a lot of good things. They’re getting to the net.”

The Sharks liked a lot of what they did against the Maple Leafs, as they peppered Bobrovsky with 30 shots, including 13 in the second period.

But special teams were the difference Monday, as the Sharks went 0-for-4 on the power play, and the Leafs went 2-for-5.

Auston Matthews’ power-play goal with 12 seconds left in the second period tied the game 1-1, and Gavin McKenna’s man-advantage goal 4:56 into the third period put the Leafs ahead for good.

Matthews’ goal came after the Sharks were whistled for too many men, and McKenna’s goal came after Luca Cagnoni was called for cross-checking Brandon Duhaime.

Sharks captain Macklin Celebrini said the too-many-men call was due to a miscommunication. From the bench, Celebrini jumped on the ice thinking Michael Misa was coming off, but the second-year center stayed on.

“That’s on me,” Celebrini said.

The Sharks have lost four of their last five games but feel their game is close.

“We’re not playing bad hockey,” Celebrini said. “We’re in all these games, and it’s just the little stuff, the details that have cost us games down the stretch, and then tonight kind of not executing when we need to.”

“I think we’re all right. We know we can feel it. We’re not scoring right now. We’re getting some good looks. We got some good chances,” Warsofsky said. I thought (Bobrovsky) played really well, but there are still some consistency issues in our game, just all over with the puck and without it.”