The Wings have confirmed influential midfielder Jack Jebb is out for the rest of the season.
The injury picked up against Slough Town on Saturday is worse than first feared.
Manager Steve King says he will be a big loss to Welling but backs Jebb to bounce back.
“Jack Jebb unfortunately sustained an injury in the game on Saturday to his left knee,” King said
“Following an MRI scan it has been confirmed he has broken off a piece of articular cartilage from the weight bearing portion of the lateral femoral condyle .
“He will now undergo arthroscopic surgery to remove the loose fragment and potential microfracture surgery followed by an intensive period of rehabilitation which will keep him out for the remainder of the season.”
Welling are up to second place and haven’t lost a match since mid-August.