Isn't that the same kind of injury Stanbach had when we drafted him? Think he was injuried in October but was ready to go by TC (late July) except by then he had shin splints which slowed his recovery til end of TC.
Anyway it usually it does take about a year but a good rehab program could have Freeney back on the playing field by the season opener. I don't know whether his age could slow his recovery.
It will be tough for him to ever be the same player after that injury. His game was all about peed and quickness. If he comes back 85-90% of what he was, he is just another player. Nothing special and certainly not worth his contract.