The Swede was unable to make it to the end of PSG's 3-1 win over Chelsea after stretching his leg as he ran forwards in the second half, and was swiftly substituted
Midway through PSG's 3-1 defeat of Chelsea on Wednesday, the former AC Milan and Barcelona forward pulled up with what looked like a hamstring injury, but it has since been suggested could have been his calf causing him pain.
The Swede made a pass out wide but pulled up as he sprinted forwards in pursuit of a potential return ball with 66 minutes on the clock.
Laurent Blanc brought on Brazilian winger Lucas Moura, with Ibrahimovic grimacing as he shuffled down the tunnel, casting doubt on whether he will be fit for the return leg at Stamford Bridge and even the rest of the season.
And PSG chief Al-Khelaifi was not optimistic, telling beIn Sport after the match: "Ibrahimovic picked up an injury. He will be out for a few weeks."
Ibrahimovic's absence in Ligue 1 will be less obviously felt as les Parisiens are well ahead of second-placed Monaco in the title race and coach Blanc added that it was beyond question that at least a short spell on the sidelines is needed.
"Zlatan felt a slight muscular pain - I'm not sure whether it's his calf or his hamstring," Blanc added. "We'll have to look after that but it will require a certain amount of rest."
Eight minutes after Ibrahimovic made way for the hosts, Marco Verratti suffered a similar fate as he was forced off the pitch with an unspecified injury as January signing Yohan Cabaye came on in his place.