The utility player, who has been with the Rocks for nearly a decade, faces up to two months out after coming off during the 2-2 draw at Nyewood Lane.
Jack Pearce's team are struggling for form in the Vanarama National League South and now have to get back to winning ways without experienced Crane.
"James suffered a very bad dislocation of his shoulder, but fortunately there was no fracture. His shoulder is now in a sling and is expected to stay that way for two weeks," the club confirmed this morning.
"He has been advised that he will not be able to play for around six to eight weeks."
The announcement went on: "It is sad to see any player receiving a serious injury, but James having been such a magnificent servant of the club over the past nine years or so makes it even harder.
"He has now played over 400 matches for the Rocks and of course has scored some memorable and vital goals for us."