Matt Niskanen left Wednesday's game with a lower body injury and did not return.
The Flyers scored three times, including one just 23 seconds into the game, but two disallowed goals allowed the Caps to reset. Washington took advantage with the 4-1 win.
The Caps have lost both of their games since returning from the bye. They will look to snap that skid Wednesday against the Flyers (8 p.m., NBCSN).
Capitals Rewind: In the first game back from their bye week, the Capitals lost to the Detroit Red Wings in a shootout.
NHL Power Rankings
Taking you through the ups and downs of the NHL season. Which teams are hitting their stride and which teams are struggling? Find out where all the teams in the NHL stand with the NHL power rankings.