Michele Campagnaro is a major doubt for the Six Nations after the Italy and Exeter Chiefs centre suffered a serious knee injury.
Campagnaro is expected to be out for at least six months due to ruptured cruciate ligaments sustained in the Chiefs' pre-season friendly against Cardiff Blues last weekend.
The 24-year-old left during the second half of the Premiership champions' 21-20 defeat at Cardiff Arms Park on Saturday and will undergo surgery.
"They are going to operate as soon as possible, once the swelling goes down," Campagnaro told Gazzetta dello Sport.
"As for getting back to competition, that could be six months or more, possibly eight or nine."
The loss of Campagnaro is a blow for the Chiefs, who start the defence of their title against Gloucester on Friday.