AVB worked for Mourinho at Chelsea before launching a coaching career of his own.
"It was a unique experience. It is very difficult to find someone with such professionalism, dedication and knowledge of the game. Fortunately, I saw a good professional in observing the games and in the study of adversaries. It was a privilege to work with him and to know his training methodology," said Villas-Boas.
"Mourinho is perhaps the best coach of all time."