France centre Wesley Fofana fractured a rib in Friday's Six Nations defeat to Wales and will almost certainly miss the rest of the tournament.
The 26-year-old could be sidelined for up to a month, which means he is highly likely to miss France's final two games against Scotland on March 8 and Ireland a week later.
France are level on points with Ireland, England and Wales after three matches.
Toulouse star Gael Fickou is likely to replace the Clermont Auvergne centre.
The news is a big blow for France. Fofana has been a key man in their back line, and he has forged a highly effective midfield partnership with Mathieu Bastareaud.