Napoli striker Arkadiusz Milik will be out for some four months after undergoing knee surgery on Monday, the Serie A club said on their website (www.sscnapoli.it) on Monday.

The Poland international injured his right knee late in Napoli's 3-2 win at SPAL on Saturday.

The Neapolitan club said the 23-year-old suffered a complex lesion and that he would recover in a time frame similar to his previous knee injury.

Milik, capped 36 times by his country, suffered a cruciate ligament injury to his left knee last year which sidelined him for four months.