Marseille will be looking for its fourth straight win when it hosts second-place Monaco on Sunday.
In PSG's opening match, it scraped a point against 10-man Montpellier and then needed a late goal to salvage a point at home against Ajaccio before grinding out a 2-1 victory at Nantes, despite fielding four players each costing more than 40 million euros ($52.5 million).
Hardly the kind of form that is going to send a message across Europe that PSG is going to become as it hopes a Champions League contender.
"I don't think the players are at their best yet, physically," Blanc said. "Every match should bring us closer to the level of physical fitness we need. It will come, that's for sure."
Part of PSG's problem may be that it's no longer just about Ibrahimovic.
PSG signed Uruguay striker Edinson Cavani to a five-year contract for 64 million euros ($84 million) in the fifth most expensive transfer in history. But the potentially mouthwatering partnership has yet to click.
"We have to find the balance," Blanc said. "We can't play with all the attacking players we have in our squad. It's down to us to find the right system and there is also competition for places."
Playing two of the best strikers in the world together sounds easy, and Cavani has made a decent start with two goals. But Blanc has yet to find the best way to play them together.
Ibrahimovic is a center forward who likes to drop back into a provider's role, meaning that he moves into the space that Cavani needs to make his runs from deep or from off the flanks.
Blanc would ideally like Ibrahimovic to stay more central, but he showed last season that on the football field he more or less does what and goes where he wants.
Marseille does not have PSG's riches but it has a level of teamwork and understanding that PSG craves.
Coach Elie Baup did well on limited resources to secure a second-place finish last season and the team has picked up where it left off.
Striker Andre-Pierre Gignac once so portly that he was nicknamed "Big Mac Gignac" and mocked by fans for his love of junk food looks fitter than in the past and has scored in every game so far.
Marseille has scored six goals and conceded one, showing that the defense, and particularly goalkeeper Steve Mandanda, are in fine form.
Meanwhile, Lyon needs to bounce back from its Champions League setback with a win at Evian.
Lyon lost at Real Sociedad 2-0 on Wednesday and 4-0 on aggregate, failing to make the group stage of the competition it used to qualify for so easily.
Lyon needs the money and failure to qualify will doubtless impact on the remaining few days of the transfer window.
President Jean-Michel Aulas is desperate to sell striker Bafetimbi Gomis with Premier League club Newcastle eager to sign him but the striker refuses to go and has been banished from the first team.
After selling striker Lisandro Lopez, Lyon played against Sociedad without a recognized center forward and the situation bordered on the absurd with Gomis tweeting during the match that he was having dinner with his girlfriend in a restaurant.
Also Saturday, it's: Bastia vs. Toulouse; Lorient vs. Valenciennes; Reims vs. Nantes; Rennes vs. Lille; and Sochaux vs. Ajaccio.
Saint-Etienne hosts Bordeaux and Nice faces Montpellier in Sunday's other games.
