The 47-year-old insists the French champions will have more than Monaco to fend off in their bid to defend their crown and expects a tough test against Nice this weekend
Les Parisiens currently sit atop the table with 28 points after 12 games, with Lille and Monaco trailing by just two and three points respectively following Lille's victory over Claudio Ranieri's men.
With Lille firmly in the race for the title in the early part of the season, Blanc believes Rene Girard's side are just one of five who can challenge for top honours in 2013-14 - despite PSG and Monaco remaining firm favourites.
"[Lille] are nicely set with their keeper [Vincent Enyeama] demonstrating his qualities," Blanc told reporters.
"They proved that they are contenders, even if you [the media] say that the championship would be played between Paris and Monaco.
"In my opinion, five teams can join in the fight for the top three places.
"There's pressure everywhere, because you are always trying to meet your objectives."
PSG host Nice on Saturday after a disappointing midweek draw with Anderlecht, but Blanc is hoping to have Edinson Cavani back in the line-up as he looks to bounce back against Claude Puel's unpredictable outfit.
"[Cavani] should be in the team – he had a very good session on Thursday. He is getting better," said Blanc.
"He has made efforts to adapt to his new environment. When he arrived, he returned from the Confederations Cup and a long season with Napoli.
"He arrived tired and so we had to give him time. Now this work is paying off. He only has to rely on his performance on the field.
"[Puel] is a competitor, so I think he will come to Paris without renouncing his philosophy of the game.
"I hope they demonstrate their ambition on the field, because it is often synonymous with an open game.
"I did not see it [the draw with Anderlecht] as a warning. This match was very important, but we will have the opportunity to catch up against Olympiakos. I thought it would be a tough game.
"Today we have already switched our focus to Nice. The championship is a different competition and we are therefore focused on this game."
Blanc also revealed that Zlatan Ibrahimovic - who struck the equaliser against the Belgian champions in midweek - is gunning to play on Saturday despite struggling with a knee injury.
"We try to preserve [Zlatan's] knee, and I think that all his problems will disappear with time. This is a good thing for us and for his selection for the team," he added.
"He has not asked to be spared because he is a competitor. He loves to play and he trained to play. He worked very well this week."