Penguins' Sidney Crosby out of Game 4 with concussion

— -- Pittsburgh Penguins captain Sidney Crosby will not play in Game 4 against the Washington Capitals on Wednesday because of a concussion he suffered in the third game, coach Mike Sullivan said on Tuesday.

Crosby has a concussion history and missed the first six games of this season because of a concussion. He is now in the concussion protocol, Sullivan said, and listed as day to day.

Crosby left Game 3 of his team's playoff series, a 3-2 overtime loss to Washington, after he took a first-period cross-check to the head from Capitals defenseman Matt Niskanen.

Crosby lay on the ice for several moments before slowly getting up and skating off, mostly on his own power. He went directly down the tunnel for treatment. His leg also bent awkwardly during the collision. Crosby did not return to the game.

Niskanen received a major and game misconduct penalty for the hit. An NHL source told ESPN's Craig Custance on Tuesday that Niskanen will not have a hearing with the league regarding further discipline.

Sullivan would not give his opinion on Niskanen's hit after the game. But the Penguins' Chris Kunitz was not as reluctant to talk about it.

"I like Nisky as a person," Kunitz said. "I don't think it's a very nice hit. I don't think it's something this game is looking for, especially against someone who means so much to our team."

"We saw him laying there, and obviously it was tough to see," teammate Justin Schultz said. "He's our best player, best player in the world, and we hope he's all right."

The hit from Niskanen, a former Penguins teammate, came as Crosby was already going down after getting clipped by Alex Ovechkin while driving in on Capitals goalie Braden Holtby.

Niskanen said after the game that he wasn't trying to hit Crosby in the head, explaining that Crosby was moving "lower and lower" as the two came together in front of the Capitals' net.

"I hope he's OK. I certainly didn't mean to injure him," Niskanen said. "It was an unfortunate play."