The head coach had been hopeful that Ibrahimovic would recover from a troublesome heel injury in time to face his former club, but the Ligue 1 champions confirmed on Monday that the Sweden international would not be available.
It represents a blow to PSG ahead of their UEFA Champions League Group F encounter in Paris, with the French club already without captain Thiago Silva and forward Ezequiel Lavezzi with hamstring complaints.
But Blanc sees the clash as a chance for his side to show their strength without their talismanic striker.
"It is the game that we will manage to find our level of last year," he said.
"We can put in a good performance if we can be determined and more aggressive.
"Without Ibrahimovic it is not easy. We must have a good collective to compensate for his absence.
"The technical staff did everything to try to recover Ibrahimoivc as soon as possible. It is hoped he will return for Monaco [on Sunday].
"The philosophy of Barcelona is to have the ball and to be dangerous. That is what I want for us. We need to be convinced that we can succeed in beating Barcelona, individually and collectively."
The two sides met in the quarter-finals of the 2012-13 Champions League, when Barca progressed on away goals after a 3-3 aggregate draw.
