Italy captain Sergio Parisse has declared himself unfit for his team's opening World Cup clash against France at Twickenham.
The 31-year-old Argentine-born Number Eight, capped 112 times by Italy and their star player, has not fully recovered after undergoing surgery to drain a haematoma last Monday.
He picked up the injury, a swelling of clotted blood, in a muscle in his left leg in Italy's World Cup warm-up defeat to Wales in Cardiff last weekend.
The Italian Rugby Federation initially said Parisse would not meet up with the Italy team in Rome on Saturday but would instead link up "at a later date" in England.
Italy coach Jacques Brunel played down Parisse's absence, but admitted the experienced Stade Francais player, considered one of the world's best in his position, would be missed.
"We've played without him before, so we'll find a solution," said Brunel.
"But we'll undoubtedly miss him because he's a very influential player for us."
Italy team manager Luigi Troiani said Parisse will undergo further tests on Monday to see whether he would risk developing thrombosis by flying back to Italy from France, where he is based.
Troiani said he hoped Parisse would return in time for Italy's fixture against Canada at Leeds' Elland Road ground on September 26.
"For the moment, there's no point in him making the trip. We have to see how his injury develops, we're in contact with the medical staff at Stade Francais," said Troiani.
"So Sergio will remain in Paris for the moment and won't be back here until Tuesday or Wednesday and when he does he will come by train.
"We don't want to complicate things, and he simply won't be ready to play against France anyway. We hope to have him back for the Canadian game."
After the Group D curtain-raiser against the French, Italy face Canada, Ireland and Romania.