The Albania international full-back has been mooted as a possible summer addition at Old Trafford and Emirates Stadium, having figured on Premier League radars for some time.
At just 23 years of age, Hysaj is considered to be a useful performer for the present and a hot prospect for the future.
Mario Giuffredi told Radio CRC: “There are several scouts who have come to view him, representing German and English interest, but we have no need to leave Napoli.
“Elseid is in his second season at Napoli and I think he can do well next term as well.
“The lad really wants to fight for the Scudetto, so both his intentions and those of Napoli coincide.
“Having said that, Hysaj has a release clause in his contract and if a club arrives that is intent on paying it, the player could leave.
“If that were to happen, we’d keep Napoli fully in the loop on everything and wouldn’t take any other paths without informing the club first.”
Hysaj has made 43 appearances for club and country this season, with his position at right-back firmly cemented following a 2015 transfer from Empoli.