Spurs are determined to land the Internacional star, 20, for around £6million.
Sandro's agent Luiz Paulo Chignall said: "This deal is very advanced although Internacional are yet to receive some important documents."
Sandro, capped once, played what is expected to be his last game for his club this week.
He said: "I don't want to speak too much about this but I am ready to move to Europe. I am convinced my style will suit a team that favours an attacking approach."