The Sweden international was forced off in the 68th minute of PSG's 3-1 UEFA Champions League quarter-final first-leg win against Chelsea on Wednesday, and will miss the second leg next week.
Ezequiel Lavezzi got them off to a flyer, scoring after just four minutes to give them the perfect start, but reported PSG target Eden Hazard levelled from the penalty spot after 27 minutes.
An own-goal from David Luiz just after the hour mark restored their lead and Javier Pastore netted what could be a crucial third in stoppage time, but the win came at a cost.
Ibrahimovic pulled up due to the innocuous injury with 22 minutes to go and club president Al Khelaifi confirmed on Thursday that he is unlikely to return until the season's closing stages.
"He won't play at Chelsea. It's impossible," he told RMC.
"We are waiting for the test results but I think he will be out for at least four weeks."
