Penguins' Sidney Crosby out for Game 4 because of a concussion

NHL's leading scorer was double-teamed and sent to the ice on a shove from Matt Niskanen in Game 3

The Pittsburgh Penguins might very well be the No. 1 team remaining in the Stanley Cup playoffs. But for the time being they are without Sidney Crosby, who will miss Game 4 against the Washington Capitals, at least, because of a concussion suffered in Monday's overtime loss in Game 3, coach Mike Sullivan said Tuesday.

The NHL's leading goal-scorer was knocked out less than six minutes in Monday night, thanks to a cross-check from the Caps' Matt Niskanen. Washington went on to win 3-2 in overtime.

oye ..Sidney Crosby gets it from both ends! Skate pulled underneath him by Ovechkin & Niskanen finishes the takedown pic.twitter.com/0TWZwmGHXp

— HabsHappy: JeSuisCH (@HabsHappy) May 2, 2017

Another angle of the hit shows Crosby near the net, stumbling from his encounter with Alex Ovechkin before running head on into Niskanen's blow:

Another look at the Crosby injury. Ovechkin also got him with the stick up high & took out his leg just prior to the Niskanen hit pic.twitter.com/Z0TAbKJXyv

— Pete Blackburn (@PeteBlackburn) May 2, 2017

And another, at regular speed, makes it hard to tell whether there was much intent to the blow:

Alternate angle on Matt Niskanen's cross-checking game misconduct against Sidney Crosby. Looks a little bit more reflexive from here. pic.twitter.com/JRRj2WeWkF

— Jeff Veillette (@JeffVeillette) May 1, 2017

Call the hit what you want, but all eyes are on Crosby's health and how quickly he can get back onto the ice -- and whether he will at all in these playoffs.