Les Phoceens, who currently lead Carlo Ancelotti's men by three points at the top of Ligue 1, triumphed 3-0 in this fixture last season, thanks to goals by Loic Remy, Morgan Amalfitano and Andre Ayew.
Pastore admitted that the atmosphere in the stadium will make it tough for Les Parisiens, especially in a fixture where rivalry runs deep.
The Argentinian believes that, no matter what the outcome, it has all the ingredients for a classic encounter.
"The atmosphere in Marseille is fantastic, and they're going to be desperate to win," Ligue1.com quoted the 23-year-old as saying.
"It's definitely going to be tough for us, they have a great stadium with great fans.
"We'll really have to be on the ball to get a result, but whatever happens I think it'll be a great match."
Marseille have a perfect record in Ligue 1 so far this season.