France captain Jerome Thion is in hospital with a fractured larynx and will be sidelined for at least six weeks after being elbowed by South Africa's John Smit in Saturday's match.
"Jerome spent the night in hospital on a ventilator. He had a scan but we'll have to wait for two or three days to know the extent of the injury," a spokesman for the French team said.
The incident occurred 12 minutes into the game at the Stade de France when Springbok skipper Smit charged Thion and caught him in the throat with his elbow.
The touch judge reported the incident to the referee who awarded a penalty to France which Jean-Baptiste Elissalde converted. France won the game 26-20.