The injury occurred on Tuesday during the second period of the Flyers' 3-0 loss to New Jersey. He was hit in the skate by a shot from teammate Kimmo Timonen.
Hartnell is in his 12th NHL season, the last six of them having been spent with the Flyers. He is coming off the best year of his career, one in which he scored 37 goals and recorded 30 assists.
Notable deaths of 2014 [PHOTOS]