— Sens Communications (@Media_Sens) November 14, 2021
Pinto, who was reactivated off injured reserve before the game, had previously been sidelined with an upper-body injury.
With the Senators leading 3-0 midway through the second period, Pinto leaned down and took a faceoff when he grabbed his right shoulder with his left hand before skating off the ice and going directly to the dressing room.
Pinto was expected to return to a prominent role after being sidelined for nine games, playing centre on the Senators' second line and second power-play unit against the Penguins. The 21-year-old American has one assist through four games this season.
The Senators, 3-9-1 entering the game, have struggled with injuries and COVID-19 outbreaks this season.