Potential bidders for Victor Osimhen have been put on alert by comments from Napoli club president Aurelio De Laurentiis.
Chelsea have been tracking the Nigerian striker for some time but have been put off by a price tag reaching £150million, while Arsenal, Liverpool and Real Madrid have also been linked.
Talks are ongoing between Osimhen's camp and Napoli over extending his contract beyond the summer of 2025.
Despite rumours of a three-year extension being agreed in the summer, De Laurentiis has opened the door to cashing in on his player in the coming year - just as he did when selling Kalidou Koulibaly to Chelsea two summers ago.
"I have never been unhappy with Osimhen," he told reporters.
"But there are always two people in these things; I have remained the same, if his mood has changed I can't do anything about it.
"If after a handshake things change, it's disappointing, but we take note of it and then life goes on.
"We have excellent relations with him, his contract expires in 2025, so there is time. Don't forget that I sold Koulibaly in his last year."
Reports in Italy state that Osimhen, 24, and his agent, Roberto Calenda, have not taken De Laurentiis' comments well amid the stand-off over his contract.
Napoli's social media channel was accused of mocking the forward in recent TikTok posts and the relationship between the two parties is described as tense.
Should Osimhen be put up for sale in the final 18 months of his contract, it is likely his valuation would be significantly decreased.