He told La Vanguardia newspaper: "(Messi) is leading the team to be one of the best ever - it is thanks to him that we have won so many titles.
"It is a pleasure to have him play for us, and he plays the same way as he did when he was 13, only now he does it more professionally and against the very best.
"We can only hope he keeps his level up for the maximum time - if he can improve that would be great. But we should not ask for anything more, and if he continues his love for the game it will keep him at the top for many years.
"It takes many years to get to the top level, and Leo is the best in the world."