Pastore has revealed that he is prepared for a tough match and admitted that PSG will have to be at their best to win the away encounter.
"It's a very important Clasico this season because Marseille are top of the league and we have the chance to move closer to them," Ligue1.com quotes Pastore as saying.
"It's important for the fans too. This is the biggest game of the year, so we'll prepare in the best way possible and make sure we're focused and mentally strong."
"We'll really have to be on the ball to get a result, but whatever happens I think it'll be a great match."
PSG are currently three points behind Marseille in second place in Ligue 1.