Fiji born and former All Blacks wing Sitiveni Sivivatu is out for four months after a disastrous start with his new French club.
After three years with Clermont, Sivivatu moved to Castres in the off-season, but he injured a shoulder in Castres final pre-season game with Brive.
Specialist advice has confirmed he now needs surgery, meaning he will be out for a long time.
Meanwhile in the Rugby Championship, the All Blacks face the Wallabies at 10.05pm this Saturday while the Springboks face Argentina at 3.05am Sunday.