The first series of injuries have come out for the New York Rangers as Carl Hagelin and Ryan Callahan both underwent successful shoulder surgery earlier this morning. Both Hagelin and Callahan had identical injuries as they had torn labrum's in their left shoulders. Callahan's surgery likely stems from his shoulder injury earlier in the season in a fight with Max Talbot of the Philadelphia Flyers. Hagelin, on the other hand, had no previous shoulder injuries during the season, so it's tough to say when he suffered his injury.
Marian Gaborik had similar surgery during last year's off-season, and the recovery time was somewhere in between 5-6 months. According to Andrew Gross, the expected timetable for both Callahan and Hagelin is in the range of 4-5 months. With that timetable, there is a chance both could be ready for the start of the year, and there is also a chance they could miss at least a month of the regular season.
Either way, recovery time for a torn labrum is very hard to predict. While doing a little research on recovery times for this exact surgery, I found there are many different factors that go into it. They range from where the tear was located, how severe the tear was, and how well it was surgically repaired. It also stated it takes around 4-6 weeks to reattach to the bone, and another 4-6 weeks to regain strength.
Right now, it's too early to predict any recovery times. It all depends on their severity.