The Penguins center left during a television timeout with 5:43 remaining in the second period, roughly one minute after his last shift.
Pittsburgh coach Mike Sullivan said after the game that Crosby was still being evaluated.
The Penguins have a 3-2 lead in the best-of-7 series. Game 6 will be at Pittsburgh on Friday.
"Obviously, you don't want to see anyone get hurt, and obviously 'Sid' is a real important player for us," Penguins forward Teddy Blueger said. "Throughout the course of the year, we played without him and done pretty well. We battle through injuries, so I don't think it's anything we can't overcome."
Crosby took a hard hit from defenseman Jacob Trouba in the Rangers zone at 9:15 of the second. He fell to the ice, got up and immediately skated to the bench. Crosby returned for two more shifts before leaving the game.
He played 15 shifts totaling 10:49 of ice time and was on the ice for forward Jake Guentzel's first goal that gave Pittsburgh a 1-0 lead at 10:28 of the first period.
New York scored three goals in 2:42 after Crosby left to take a 3-2 lead, but Guentzel tied it 3-3 by scoring his second goal with 1:54 remaining, 13 seconds after Trouba put the Rangers in front.
Crosby leads the Penguins with nine points (two goals, seven assists) in the series.
