Hamsik had been due to feature in his country's opening game against the United Arab Emirates on Thursday at the Rajamangala Stadium in Bangkok, but will now stay in Italy to recover.

The 30-year-old missed a handful of training sessions in January with tonsillitis and a decision was made on Wednesday to undergo a small operation to remove his tonsils.

"Marek Hamsik was operated on this morning at the Ruesch Clinic by Professor D'Angelo, who practiced a tonsillectomy," read a statement on Napoli's official website.

"The surgery was perfectly successful. Hamsik will return home tomorrow and will not participate with the Slovakian national team."

The King's Cup also features Gabon and defending champion Thailand, with the final taking place on Sunday.