"The objective is for him to play again before the end of the season. It's a realistic target. The signs are good, but we can't just do anything with him for fear of a recurrence," said Blanc at a press conference prior to PSG's Ligue 1 meeting with Evian at the Parc des Princes on Wednesday.
Ibrahimovic injured his right thigh in the first leg of PSG's Champions League quarter-final against Chelsea at the start of this month and then returned to Sweden for a week for personal reasons before coming back to the French capital on Monday.
The Swede, who has scored a club record 40 goals in all competitions this season, missed last Saturday's 2-1 win against Lyon in the League Cup final as PSG secured the first of a likely trophy double.
A win against Evian on Wednesday will leave the defending champions 10 points clear of second-placed Monaco with only four games left and will mean they can clinch another Ligue 1 title with a win at Sochaux on Sunday.