Lens forward Issam Jemaa is set to be sidelined for around three months with a thigh injury.
The Tunisia international picked up the problem in last Saturday's 1-1 draw with Toulouse.
He was replaced by Toifilou Maoulida shortly before half-time and it has now been revealed that he is not likely to return until February.
"I tore a muscle," Jemaa told the club's official website. "I have to wear a plaster up to just above the knee for a month and a half and then, for another month and a half, I will be in rehabilitation.
"For now, I will stay at home and rest.
"I have to go back next week to aerate the plaster and then two weeks after that to have it changed, because right now my knee is bent at a 30-degree angle and the doctors will have to sort that out."
Lens coped well in Jemaa's absence on Sunday as they overcame Montpellier 2-0 at home.