Paris - Clermont's former All Black Isaia Toeava is expected to be out for six months, the club said on Monday, after injuring his shoulder in the 49-24 European Challenge Cup win over the Dragons at the weekend.
The 32-year-old, who has scored three tries in ten starts in the Top 14, lasted just 10 minutes against the Welsh side before leaving the field.
"The Clermont back underwent medical examinations this afternoon which revealed a rupture of the rotator cuff of his left shoulder," said Clermont on their official website.
"It will be operated on at the end of the week."
Toeava played 36 times for New Zealand before joining Clermont in 2016.
He is unlikely to play again this season.
It is further bad news for the side who currently lead the Top 14 after in-form winger Alivereti Raka and France prop Rabah Slimani last week were ruled out for up to three months with injuries of their own.
Clermont have won all four of their Pool games in the Challenge Cup.