Zlatan Ibrahimovic could need surgery on the heel injury that has sidelined him for more than a month, according to reports in the Swedish media.
The Sweden captain and Paris Saint-Germain star, accompanied by a PSG physiotherapist, returned to his native country earlier this week to seek medical advice on the problem.
Aftonbladet reported that Ibrahimovic was suffering from an inflammation on the bottom of his foot which could need an operation to put right.
RMC said PSG had hoped that last season's leading goalscorer would be fit for their Champions League game against APOEL Nicosia on Nov. 5.
"It's difficult for us," teammate Lucas told the French radio station. "Zlatan is a great player. He's our benchmark. I'm sad for him, because he's also our friend. I hope he'll play soon. We're going to help him because we need him. We miss him a lot."
When Ibrahimovic, 33, joined up with the Sweden squad ahead of their recent Euro 2016 qualifiers, neither an examination by medical staff nor an MRI scan had diagnosed the injury.