Didier Zokora's future at Tottenham is in doubt.
The Italians will accept half of the £7million transfer fee up front - with the rest payable based on appearances.
Former Chelsea midfielder Tiago, 26, hardly got a look in at Juve but will pick up £35,000 a week at the Lane.
The Blues sold him to Lyon to make way for Michael Essien.
Tiago, who snubbed a move to La Liga, is now expected to displace Zokora at Spurs.