Edinburgh coach Andy Robinson admits it is a significant blow to lose Dave Callam for the rest of the season - with six months of this campaign still to play.
The Scotland number eight, who began this year’s RBS 6 Nations in the starting line-up, has had surgery to repair a serious hip injury.
Callam, 25, had the operation after a scan revealed a potentially career-threatening bone cyst on his hip.
Robinson, now Scotland assistant coach, said: "It was a very unfortunate injury and we all feel for Dave..
"Obviously the recovery period now is very important for him. We are hoping David comes back stronger than ever in time for next season."
"I was devastated at first as it's a rare injury to find in a young sportsman," the talented forward said.
"But fortunately we found out when we did as it could have had serious repercussions on my rugby career."
Callam, who has 11 times caps for Scotland, only played once for his club in the league this season.