Niskanen exited Sunday's game due to a left hand injury and it is unclear if he will return.
Washington Capitals last injuries
Philadelphia Flyers last injuries
Myers is battling an illness and it is unknown if he will suit up against the Canadiens on Tuesday.
Morin is battling an illness and will not play against the Canadiens on Tuesday.
Giroux is battling an illness but is expected to play Sunday versus the Penguins.
Morin has been removed from the injured reserve list where he is recovering from a torn ACL but it is unclear when he will make his season debut.
Voracek has been suspended two games for inference against an opponent. He is likely to be reinstated in time for Friday's contest versus the Maple Leafs.
Hart is sidelined with an ankle injury but is projected to return Monday against the Senators.
Voracek has been held out the past two games due to a lower-body injury but it is expected he will suit up against the Islanders on Saturday.
Patrick sat out the previous game due to a concussion and his availability is likely for Saturday's tilt against the Islanders.