Ligue 1 leaders St Etienne have been rocked by the news that Boubacar Sanogo needs an operation.
The Ivory Coast international is nursing a thigh injury and will require surgery in order to rid himself of the complaint.
It is expected that he will be sidelined for up to 12 weeks, meaning he is unlikely to figure again before the winter break.
Sanogo struggled to live up to expectations upon joining St Etienne from Werder Bremen last season, scoring only one goal in 17 games.
He is, however, a proven goalscorer and was expected to lead the line again for Christophe Galtier's men this term.
Meanwhile, St Etienne have revealed that Yoann Andreu will also be going under the knife in the next few days.
The full-back, who has progressed through the club's academy ranks, is struggling with a groin problem.
He will require up to three months of rehabilitation before he can be considered for first-team duty again.