The 27-year-old has picked up a calf injury. Fae has been struggling with calf problems in recent years.
“After the match against Caen he felt a muscle strain in his thigh,” Roy told L’Equipe.
“We thought it was not very serious and he would miss five or six days. But two days later he had calf pain. He had medical examinations and a new problem was found.
“It is a bad blow for him because he has made a lot of effort to get back to his best and it is a bad blow for the team because we know what he is capable of.
“He will now have further examinations and meet with specialists.
“We hope he will be back in around six months, just like he was the last time he suffered this problem.”