Couturier hasn't skated with the Flyers in roughly 14 months. Couturier is coming off of consecutive back surgeries, most recently in October. The initial diagnosis was 3 to 4 months for an estimated return date, but there still hasn't been any news. Since there hasn't been an update recently on the condition or recovery, Couturier most likely isn't near ready for a return.
The Flyers are also currently 9 points out of a Wild Card spot and are trending in the wrong direction. The Flyers are 3-4-3 in their last 10 games and have a -26 goal differential on the season. There are only two teams with a worse goal differential in the Eastern Conference. Rushing Couturier back to help the Flyers already thin chance of seeing playoff hockey only puts him at risk for another injury, which would significantly hinder the Flyers success next season.
While it is a difficult situation, Couturier coming back this season would be a mistake. Back surgeries in the NHL or any professional sport are difficult to come back from. They take time to heal and are tougher to recover from. Since there are no reports of Couturier even skating, he most likely isn't anywhere near game shape. Even though his presence give the Flyers a more likely chance of achieving the nearly impossible, it would be smart for everyone to let him fully recover and hopefully come back next year stronger than ever.