Napoli president Aurelio de Laurentiis admits Dries Mertens could leave for China.
Mertens signed a new deal to 2020 on Friday night.
"Last night I had a meeting with Giuntoli, Chiavelli and Mertens' entourage," President De Laurentiis told Radio Kiss Kiss Napoli.
“We were together from 14.30 in the afternoon to 1.40 in the morning, including our lawyer, the lawyers from Belgium, his Milanese consultants, financial experts on the phone and after hours of technical discussion, we all worked out a perfect bilateral agreement for Dries and Napoli.
“It protects the fans and me. Dries will stay with us for a few more years, unless of course he wants to go to China and next year someone pays the release clause that he wanted introduced and I cannot refuse.
“I was not in favour of the release clause after the Gonzalo Higuain mistake, but we learned from it, so there is a release clause on Dries' contract that is valid only for China.
“Relax, Mr Mertens will only play for Napoli in Italy. If he is to leave, it'll be for outside of Italy."