The Portuguese is believed to have made the decision to leave 'los che' a number of weeks ago, but despite that decision, his current employers are not willing to let him leave for less than their €25m asking price.
It is believed that Spurs' opening offer for the 23-year-old was around the €22m mark, close to the figure that Valencia are looking for, but not quite close enough to tempt them into a sale.
Mauricio Pochettino's side are still desperately on the look out for reinforcements, especially at right back following Kyle Walker's move to Man City and Kieran Trippier's untimely injury.
With the two sides so close to an agreement at an early stage there is every reason to believe that the deal will go through, providing Spurs can fight off rival interest from Serie A champions Juventus.