Rocks skipper Dan Beck is out for the season with a broken shoulder.
He was hurt when he took a heavy fall during the 4-2 win at Godalming on Saturday.
It is the latest in a long line of disruptions to the squad the Rocks management have suffered this season.
Club secretary Simon Cook said: “I spent more than three hours at Guildford A&E with poor Dan on Saturday evening and it was confirmed that he had broken his shoulder.
“It does appear to be a clear break, but he will be attending the fracture clinic in Worthing when things will become clearer.
“Dan was obviously in considerable pain and needed lengthy treatment from the paramedics when they arrived at the ground before he could be moved.
“Fortunately Godalming’s assistant secretary is a trained first aider who was extremely good in assisting Dan while we waited for the ambulance. Many thanks to him.
“Unfortunately recovery from such an injury is likely to take around eight weeks which sadly means it is unlikely that we will see Dan playing again this season.
“I am sure all supporters will wish Dan a speedy recovery.”
Beck has been one of the Rocks’ most consistent performers this season - one of the few constants in an ever-changing line-up.
The Rocks are six points clear at the top of Ryman one south with 11 games left. They host Folkestone at Nyewood Lane this Saturday.