Benjamin Mendy is facing a significant spell on the sidelines with a knee injury, according to Manchester City boss Pep Guardiola.
The French full-back is to visit a knee specialist in Barcelona after suffering the injury last weekend.
“I think it is going to be a major setback,” said Guardiola after City’s Champions League win over Shakhtar Donetsk on Tuesday.
“We are going to see finally what he has.”
Asked how long he expected Mendy – a £52m signing from Monaco in the summer – to be out for, Guardiola added: “I don’t know.
“Wait until Thursday but I am pretty sure that it will unfortunately be a little bit longer than we expected or would like.”
Asked whether he would consider looking for a replacement left-back in January, Guardiola said: “We will see in January.
“We thought next summer about looking for another left-back, another replacement, but we will see what we do.
“We have alternatives in our squad – Danilo, Fabian Delph, Fernandinho, can play there so we will see as we go along.”
Mendy will travel to see Barcelona-based Ramon Cugat, a close friend of Guardiola, who treated City duo Vincent Kompany and Kevin de Bruyne last season.