Defenseman Radko Gudas, who has several nagging injuries but could have played, was replaced in the lineup by Nick Schultz when the Flyers faced Vancouver on Thursday.
Flyers coach Dave Hakstol said Gudas needed to "play a little more consistently."
The Flyers' defensive pairings Thursday: Ivan Provorov and Andrew MacDonald; Michael Del Zotto and Brandon Manning; and Shayne Gostisbehere and Schultz.
Gudas had been paired with Del Zotto and Gostisbehere had been with Manning in the previous two games.
The Flyers-Penguins rivalry is the fourth-best in NHL history, according to the NHL Network.
It ranked the Canadiens-Bruins at No.