The most likely scenario is that Crane won't get near the first team for the rest of this season, even if he recovers after six months. Rebulding the muscle around the area will take extra time, as well regaining match fitness.
Crane was suspended for the Mariners first two games of the season through suspension and it was thought he was not in Russell Slade's immediate first team plans anyway.
With Rob Jones also sweating on a knee injury, Slade may well look for further cover despite Dean Gordon arriving at the club today.