Clermont Auvergne captain Damien Chouly requires back surgery that will rule him out of France's November Tests.
Number eight Chouly began to feel discomfort las weekend and, after sitting out Saturday's 51-20 thumping from La Rochelle, examinations showed he has sustained a herniated disc.
Clermont announced on their official website that "the unavailability for such an injury is at least three months", with an operation scheduled for Wednesday.
Chouly is consequently expected to miss the remainder of the year, which will include the start of Clermont's European campaign and France's next batch of internationals.
Guy Noves' side are scheduled to face world champions New Zealand twice, before Tests against South Africa and Japan.
Should Chouly, who has made 46 appearances for France, suffer any setbacks his participation in the early stages of the Six Nations could also come into question.