Unfortunately, it will be another lost season for him.
At best he can utilize the Flyers' medical and rehab facilities to fully recover by End of January, go on a short conditioning stint with the Phantoms to test his knee and hope that the Flyers are either well out of the playoff picture or Hägg getting injured to take his place as 3 LD to get into a dozen of games.
More likely he needs to sit out until mid February, keeps doing repetitions with Folin during practice, gets to play the last couple of regular season games.