Napoli have confirmed star fullback Faouzi Ghoulam has ruptured his anterior cruciate ligament, an injury he sustained in his side's loss to Manchester City in the group stages of the Champions League on Wednesday night.
The 26-year-old went to ground holding his knee during the first half at San Paolo and was then substituted just 31 minutes into proceedings, which subsequently saw his side succumb to a 4-2 defeat at the hands of City.
Ghoulam is understood to have feared the worst immediately after going to ground, and he was sent straight to see a knee specialist at the Villa Stuart clinic in Rome, where professor Pierpaolo Mariani has since confirmed a complete rupture of the ligament in his right knee.
The full-back is set for an operation on Friday morning, and although the club did not state a specific recovery time, the injury is likely to mean the 26-year-old is set for four to six months on the sidelines.
Ghoulam has been a dominant figure in Napoli's side this season, making 15 appearances for the club which returned two goals and three assists for the defender.
Such is his importance to Napoli, his manager Maurizio Sarri said following the Champions League fixture, via FourFourTwo: "In my view, we lost momentum with Ghoulam's injury, as it took a while to re-organise and it becomes difficult to win back possession when they press you that high up the field.
"We were hoping that eventuality would only be for a few minutes, not an hour. It's not easy to replace Ghoulam, as right now he is one of the best left backs in Europe, but we have the options."