Luiz suffered knee ligament damage while on international duty with Brazil, leaving Blanc short on defensive options as Thiago Silva also continues his stint on the treatment table.
Marquinhos is expected to partner Zoumana Camara at the back, while Serge Aurier is hoping to prove his fitness in time to play after taking a blow to the head when playing for the Ivory Coast against Cameroon earlier this week.
Rennes boss Philippe Montanier has been handed some good news ahead of their meeting with the defending champions after both Benjamin Andre and Sylvain Armand were cleared to play following knocks in training.
However, influential midfielder Christian Bruls remains on the sidelines as he continues his recovery from a foot injury.
Possible starting lineups
Rennes: Costil, M'Bengue, Danze, Mexer, Armand, Pajot, Grosicki, Henrique, Prcic, Fernandes, Toivonen
PSG: Sirigu, Digne, Van der Wiel Camara, Marquinhos, Matuidi, Motta, Pastore, Verratti, Ibrahimovic, Cavani
Sports Mole says: 1-2