Blanc is thought to be close to agreeing a deal with the Ligue 1 champions to take over from Carlo Ancelotti, who is reportedly ready to leave for Real Madrid.
However, Pires has questioned the appointment, claiming that Blanc could struggle with the egos in the dressing room at PSG.
The former Arsenal midfielder pointed towards the 47-year-old's struggle with the France national team as evidence of his inexperience.
"I like his philosophy, but he will also encounter some obstacles," said Pires. "I am curious to see how he will react to all the big egos and stars in the dressing room.
"He has never experienced anything like it before in his coaching career. And we all remember that he had some problems with the players with egos during his time in charge of France."
Blanc stepped down as coach of France in 2012.