Ibrahimovic limped out of PSG's 3-1 UEFA Champions League quarter-final first-leg win over Chelsea on Wednesday, and is expected to miss at least four weeks with a hamstring injury.
Uruguay forward Edinson Cavani will likely move into the middle to fill the void left by Ibrahimovic after operating on the right flank for much of his maiden campaign since joining from Napoli in July.
Sweden international Ibrahimovic has been in magnificent form for the defending Ligue 1 champions this term, scoring 40 goals in all competitions.
But Blanc, who expects Ibrahimovic to return in time to finish the season, is adamant he will not alter his approach as a result of the former Inter, Barcelona and Milan man's absence.
"He has a muscular lesion. He is unavailable for the coming weeks for an unspecified amount of time," Blanc said.
"Unless the injury gets worse, he will be available to finish the season. It's hard to tell because it's still fresh, it will depend on how the injury evolves.
"Our philosophy and our tactics will not change."
PSG host Reims on Saturday prior to Tuesday's second leg of their Champions League clash at Stamford Bridge as the capital club - who lead Monaco by 13 points at the top of Ligue 1 - aim to take another step towards a second successive league title.
Cavani will be looking for his first goal in six matches against Reims following an ineffective performance in midweek.
And Blanc is confident the 27-year-old will soon find form.
"Cavani is a striker who scores goals and islso a good defensive replacement," Blanc added.
"Cavani has nothing to prove. This is a great goalscorer who was injured. He will back to goals, I am sure."
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