Marseille - France international flyhalf Frederic Michalak could be out of action for up to three months after tearing a hamstring in his right leg at the World Cup.
The player's club coach at Toulon, Bernard Laporte, said that further tests would be carried out on the 33-year-old to ascertain the extent of the damage but he expected him to be sidelined for anywhere from five weeks to three months.
Michalak sustained the injury after only 10 minutes of France's nightmare 62-13 loss to New Zealand in the World Cup quarter-finals last weekend.
After the match he announced his retirement from international rugby to concentrate fully on playing for Toulon in the French Top-14, where he is under contract until the end of the season.