France centre Jonathan Danty is a doubt for their World Cup opener against New Zealand because of a hamstring injury.
The 30-year-old scored at the weekend in France's 41-17 win over Australia in their final warm-up game.
The French Rugby Federation (FRF) confirmed extra tests post-game showed a "slight problem" with his hamstring.
Danty will have further tests over the coming days, with the hosts set to play the All Blacks on 8 September at Stade de France.
The FRF added a training schedule will be "adapted to his situation" next week.
The La Rochelle centre, who is a key player for Fabien Galthie's side, is likely to be replaced by Bordeaux-Begles' Yoram Moefana or Arthur Vincent of Montpellier for the opening game.
France have already lost starting fly-half Romain Ntamack for the whole tournament due to a serious knee injury and loose-head prop Cyril Baille for at least their first two games with a calf strain.
The hosts, who are one of the favourites to win the World Cup, also face Uruguay, Namibia and Italy in Pool A.