The coach played down the Ballon d'Or nominee's influence and stressed the important of claiming the club's first title of 2014-15 with a Trophee des Champions win.
The Swede, 32, has carried les Parisiens to two successive Ligue 1 titles since his arrival from AC Milan and there have been calls in some quarters for him to be promoted to captain, such is his impact on the squad.
Blanc praised Ibrahimovic's tendency to be an inspiration to his teammates but insisted that the forward's influence does not leave the Parc des Princes' pitch.
"Saying that Ibrahimovic is the boss of Paris Saint-Germain is offensive to the board and me, as I am the head coach," he told reporters ahead of Saturday's Trophee des Champions clash with Guingamp. "He's the boss of the team, yes, but the boss of PSG would mean that he is the guy taking the decisions for everything which is not the case even if, of course, he is important.
"Ibra is a leader in the team. That's not very surprising, he's been a leader in his previous teams as well. He's a technical leader. He's a natural leader within the squad due to his personality and character, but he's not the only one. He's an important player within the squad and I am not going to deny it. He's one of the three to four natural leaders within the group."