Malkin got tangled up with Detroit's Luke Glendening, lost balance and his left skate took the brunt of a collision with the boards behind Pittsburgh's net.
The Russian forward slowly got up and kept his left skate in the air as he was helped off the ice Saturday night. Malkin was seen walking with a noticeable limp in the team's dressing room.
"He'll get further evaluated," Penguins coach Dan Bylsma said after his team's 4- 1 win.
Malkin was called for holding on the play in the third period, but couldn't serve the penalty because he was being evaluated.
Earlier in the game, Malkin went off the ice after getting shook up by a three-man hit. Glendening checked Pittsburgh's Chris Kunitz, who hit and knocked down Malkin. He got up and gingerly skated off the ice and went toward the dressing room before returning to play.
Malkin had a goal and two assists in the game, giving him 601 points in his career. He ranks among NHL leaders this season with 41 points.
He will be a key player for Russia's quest to win gold in men's hockey when it hosts the Winter Olympics in two months. That may explain why Red Wings center Pavel Datsyuk and fellow Russian appeared to be waiting to talk to Malkin outside the Penguins dressing room well after Saturday night's game.
Pittsburgh defenseman Kris Letang was a late scratch before the game because of an upper-body injury and will be evaluated along with Malkin on Sunday.
"I really don't have a great idea on either," Bylsma said when asked if the players might have long-term injuries.