Dos Santos is thought to be keen on leaving White Hart Lane, having made just 17 first-team appearances for the club since joining in 2008.
The 23-year-old has been shipped out on loan to Ipswich, Galatasaray and Racing Santander during that time, but his agent, Vicente Montes, believes that Spurs chairman Daniel Levy is making any permanent move difficult.
"As yet, no concrete offer has arrived. Giovani still has one year left on his contract with Tottenham and the market is currently in a very difficult time," Montes told calciomercato.it.
"The Spurs chairman is a tough obstacle to overcome, as confirmed by the [Luka] Modric deal. Dos Santos is held hostage by Tottenham, but at the end of his contract he'll have the opportunity to agree a deal with another club.
"Serie A and La Liga are of great interest to Dos Santos."
Dos Santos was part of the Mexico squad that won a gold medal at this summer's Olympics.