Penguins' Guentzel diagnosed with concussion after Ristolainen hit

Pittsburgh Penguins winger Jake Guentzel has been diagnosed with a concussion, according to head coach Mike Sullivan.

Guentzel was forced from the Penguins' Tuesday night tilt with the Buffalo Sabres after absorbing a blindside hit from defender Rasmus Ristolainen midway through the first period. Ristolainen was subsequently ejected from the game.

The young winger was bloodied by the hit, and didn't return to the game.

Guentzel has thrived this season on captain Sidney Crosby's wing, posting 11 goals and 25 points through 34 games.