Striker Ibrahimovic, the division's top scorer with 18 goals from 23 games, featured in last Sunday's 1-1 draw at Monaco despite back problems, but reports have indicated that he may miss Friday's clash ahead of Tuesday's UEFA Champions League last-16 trip to Bayer Leverkusen.
It remains to be seen if Edinson Cavani will return from a thigh injury, and the prospective absence of PSG's fearsome strike duo will act as a boost to relegation-threatened Valenciennes - who picked up a valuable 2-1 win against Nice last time out.
A PSG win would extend the gap at the top to eight points and increase the pressure on Claudio Ranieri's Monaco ahead of a tough trip to Bastia, who have lost just once in the league at home this season, on Saturday.
Bulgarian forward Dimitar Berbatov could be in line to make his full Monaco debut after he came on as a substitute in the draw with PSG.
Saint-Etienne are only three points behind Rene Girard's side, but face a stern test of their UEFA Champions League qualification credentials against fifth-placed Marseille on Sunday.
Jose Anigo's visitors can leapfrog Saint-Etienne with a win and boost prospects of a return to Europe's premier club competition, in which they failed to win a single point this season.
