Penguins defenseman Brooks Orpik drove Toews hard into the boards while he was trying to collect the puck. Toews skated off holding his left shoulder immediately after the collision 13:20 into the second. He did not return to the game, which Chicago lost 4-1.
Toews, Chicago's captain, ranks third on the Blackhawks with 68 points (28 goals) in 75 games this season.
"It was a big hit. I didn't really break it down," Chicago forward Patrick Sharp said. "I just saw it during the play. You could tell he was trying to hit him hard … It's tough when you see your captain get hit like that."
Orpik didn't see anything wrong with the hit.
"There was no penalty, so I don't know," Orpik said. "I think that hit happens 10 times a game."
The Blackhawks are off until Thursday, when they'll host the Minnesota Wild.