Napoli full-back Faouzi Ghoulam will spend another month on the sidelines after undergoing surgery on a fractured patella in his right knee.
The Algeria international returned to first-team training last month but suffered a setback in his recovery and required an operation.
"Ghoulam was operated on at Villa Stuart by Professor [Pierpaolo] Mariana due to a transverse fracture of the right patella," a Napoli statement announced.
"The intervention was perfectly successful. Faouzi will start rehabilitation [on Saturday]. He will be evaluated in 15 days and should return to the training pitch in a month."