I can't be the only guy in this thread who has had a plate installed near his ankle. That thing won't be normal for a year.
I'll join your club, lol. I broke both bones (tib/fib) April 12, 2011 after getting pulled down and going into the boards. Bimalleolar fracture, required a 9 inch plate on the tibia and 10 screws total. 6 weeks completely non-weight bearing, then could walk gingerly with a cane. Doc said come August when I could skate again (5 months). Ended up being December - and although technically I could "skate", any type of competitive level was just NOT gonna happen. Had the plate removed a year ago (Oct. 2012), and just not back to adult leagues. Ankle is STILL visibly swollen and gets pretty achy.
As mentioned, your leg shrinks a ridiculous amount from non-use. I did rehab at UPMCs center for sport's medicine, and the athletic trainer there who worked with me was in the Pens programs as being on their staff (not sure if he still is) and worked Sid through his ankle sprain. Helped a ton, he was amazing, but you still end up being a long way off. Ankles can just be really bad news. Worst case would probably be if he had a trimalleolar fracture and had to get the ankle temporarily fused, as then he'd have that screw removed after the bone is healed around the plate - and removal of that means another surgery, period of non-weight bearing, and rehab. The plate supports the break, but you can get small stress fractures radiating from the screw holes - which is a setback.
No way of really knowing how long though, unless they say what all was broken. If he's having surgery though, it's very likely for ORIF and it won't be a "quick" return. Hopefully his conditioning minimizes the time and he doesn't face any setbacks.