Toulouse look set to play their Heineken Cup quarter-final with Northampton Saints without the services of Nicolas Jeanjean.
The talented fullback suffered a fracture to his right tibia in a training ground accident.
Sources at the club say Jeanjean suffered the injury towards the end of Wednesday's training session.
The French international will undergo further examinations this week but is not expected to play again for his club this season.
Jeanjean has played 21 times in the Heineken Cup, including every game so far this season, scoring two tries.