The 20-year-old was injured during a defeat to Lens on February 7th.
"Following medical examinations, surgery has been scheduled in the coming days," Rennes said in a short statement.
Rennes did not specify when he would be able to return.
Liverpool reached an agreement to sign the France Under-21 international during the January transfer window for a reported 70 million euros (£61m).
Rennes sit sixth in the Ligue 1 table with 10 matches remaining this season, three points behind fourth-placed Marseille in the race to qualify for the Champions League.