St Etienne have confirmed that defender Loic Perrin will be on the sidelines for at least a month after sustaining a knee injury.
The French Under-21 international had to be removed after 20 minutes of the weekend's defeat to Marseille and initially it was feared he had sustained ligament damage.
However, the 20-year-old suffered a knee strain and will now wear a plaster for three weeks before undergoing a period of recuperation.
Perrin's absence was sorely felt as Marseille scored twice immediately after his withdrawal as substitute Fousseni Diawarra could not find his shirt to enter the field of play.
St Etienne are also lacking key defender Vincent Hognon and Perrin's injury is a body blow to their hopes for the rest of the season.