Leaders Lille expect to be without Adil Rami when they take on Caen on Saturday after the France centre-back picked up a neck injury in a 0-0 draw in a friendly against Croatia earlier this week.
"He already wants to play again but I'm not sure he's going to be ready," coach Rudi Garcia told reporters.
Rami produced an impressive performance against Croatia, but left the pitch on a stretcher in injury-time after landing badly following a spectacular bicycle-kick.
Cameroon international Stephane Mbia should replace the suspended Souleymane Diawara in Olympique Marseille's central defence in their visit to RC Lens on Sunday.
Champions Marseille are second in the standings with 51 points from 28 games, four points behind Lille.
RC Lens President Gervais Martel is confident they can remain in the top flight despite being second from bottom on 28 points, four points from safety.
"Call me crazy but I still believe in the history of this shirt. I still believe (we will stay in Ligue 1)," he told L'Equipe on Friday.
Lens's hopes were given a big boost in the previous round of matches when they beat Montpellier 4-1 away.
Montpellier coach Rene Girard will ask club president Louis Nicollin to sanction central defender Emir Spahic after the Bosnia international elbowed Lens's Issam Jemaa last month.
"There are things we cannot tolerate," Girard told L'Equipe on Friday.
Spahic has already been suspended for five matches by the league for elbowing Brest's Nolan Roux last December.
Paris Saint-Germain goalkeeper Gregory Coupet says his side cannot afford a slip-up if they are to snatch a Champions League qualifying spot.
"March was a very bad month and we now must grab points, especially at home, if we want to snatch that third place," the former France keeper told the club's website.
PSG, who take on Lorient on Saturday, are fifth in the standings, five points behind third-placed Stade Rennes.
