Saul left Real as a junior for Atletico and commented on the differences between Valdebebas and the Cerro.
He told Libero: "In everything, absolutely in everything.
"When you arrive at Atlético de Madrid they give you your big Nike backpack and the first thing the fitness coach tells you is that there are two very bad artificial turf fields that are always burned.
"And I came from the perfect fields of Valdebebas where you could play with the boots you wanted."
On the current team, Saul added: "Atlético de Madrid always gets up. Torres, Agüero, Forlán, Costa, Falcao, Griezmann, Turan ... all leave and Atleti continues because there is no one more important than the club."