Paris - Stade Francais flyhalf Jules Plisson will miss the rest of the season after dislocating his left shoulder in the Top-14 game against Toulouse on Friday.
"Thanks for your support! IRM this morning, verdict: operation Wednesday, end of season... bottom of the barrel," the France international tweeted on his account.
Plisson did not say exactly how long he would be sidelined, but the injury casts grave doubts on his fitness for the Rugby World Cup which takes place in England from September 18-October 31.
France coach Philippe Saint-Andre is due to announce an initial World Cup training squad on May 19.
The 23-year-old Plisson, who played in France's last two Six Nations games against Italy and England, was forced to leave the field in the first half of the game against Toulouse when he was injured in a tackle from hooker Corey Flynn.
The Paris side went down 21-12 and the loss of Plisson will be a big blow for their hopes of making it into the six-team Top-14 playoffs for the first time since 2009.