The full-back was linked with a January move to Milan and recent speculation has claimed that the Rossoneri will try to sign the 22-year-old in the summer.
The former Inter Milan defender suggested earlier this month that he would have to 'seriously think' about any opportunity to join Massimiliano Allegri's side.
However, Santon's representative Renzo Contract believes that the player is too valuable to Newcastle to be sold at the end of the season.
"I believe that Davide will remain in England because Newcastle want to count on him next season too," Contract told Radio Crc.
"The club believe that he still has great room for improvement."
Santon has made 63 appearances for Newcastle since his 2011 transfer from Inter and he is under contract at St James' Park for another three years.