Exeter Chiefs captain Dean Mumm has undergone shoulder surgery and is set to miss the start of the Aviva Premiership season in September.
Head coach Rob Baxter had hoped the former Australia lock would have recovered sooner from the injury he suffered towards the end of last season, but the 30-year old now looks likely to sit out at least Exeter's opening match of the new campaign.
Baxter said: "It was felt a bit of rest and rehab would sort the problem out, but it became obvious, once we got back into the start of pre-season, that the issue hadn't really improved with a block of rest, so we investigated it a bit further.
"They had an exploratory look in there, and found one or two bits and pieces that needed tidying up and sewing back together, so he has had a shoulder operation to repair some ligament damage."
However, the coach remains hopeful that the second row forward will not miss too much of the season, adding: "He is probably unlikely to feature in the first game of the season, but we are hopeful he will be back fully fit relatively quickly and it will not be a half-a-season job. Hopefully he will able to play for us sometime in that first block of six Premiership games."