The Serie A club is hoping to secure a deal for €12 million and is willing to offer the 25-year-old Spurs midfielder a five-year contract.
The 25-year-old made just 25 appearances for Spurs this season, although he was sidelined for two months with a calf problem.
Napoli is hopeful that a deal worth €12 million can be agreed with Tottenham, while the Italian club, which finished third in Serie A, is prepared to hand Sandro a five-year contract worth €10 million.
Sandro’s agent revealed last month that the player is keen on a move to Serie A but was unsure whether Tottenham would be considering offers this summer.
Meanwhile, Tottenham will keep Emmanuel Adebayor but is willing to sell Roberto Soldado, although chairman Daniel Levy is keen to recoup most of the €32 million the club paid for the striker last August.