L'OM have lost their last three matches in all competitions and their chances of reaching the last 16 of Europe's elite competition will be all but over if they fail to come past Napoli in Group F.
Visiting Napoli fell five points behind Roma at the top of Serie A by losing 2-0 to the Giallorossi on Friday night.
Gonzalo Higuain did not feature in the Italian capital but could make his return from injury at the Stade Velodrome.
Possible starting lineups
Marseille: Mandanda; Fanni, N'Koulou, Diawara, Mendy; Imbula, Romao; Ayew, Valbuena, Thauvin; Gignac
Napoli: Reina; Maggio, Cannavaro, Albiol, Armero; Behrami, Inler; Callejon, Hamsik, Insigne; Higuain
Sports Mole says: 1-2