"I'll always respect the career of [Gianluigi] Buffon, who has been brilliant. But I believe that Alisson, as a goalkeeper, is more technical with a different posture," he told Omnisport.
"He always stands assertively and is confident in what he does. Alisson is really impressive.
"In the time that we worked with him at Internacional and with the national squad, we knew he would reach a high level.
"There is more time needed to see if he can reach the top or not, but he has the qualities to stay on top and become the best goalkeeper in the world, without doubt."
Alisson has made 37 appearances in all competitions for Roma this season, while he is a 22-time Brazil international.