Former Toon target agrees Ajax move
The Dutch Under-21 star has already been touted as the new 'Frank Rijkaard' and Ajax have been trailing him for some time.
Newcastle United, along with Ajax, tried to sign him last year but the player opted to stay with Sparta - who, ironically, were at the time coached by Rijkaard.
He quit the Rotterdam club after their relegation and now the player is ready to move on.
"I think this is the best solution for me to leave Sparta," said Mendes da Silva.
"I feel I am ready for a higher level now.
"Earlier I had doubts about an offer from Newcastle United and I thought it would be much better to stay another year at Sparta."
Ajax have agreed a loan deal with Sparta, with a view to a permanent deal which could see some players moving in the opposite direction.