The Genoa goalkeeper is set to sign for the Serie A champions today.
Martinez played for Mel at Las Palmas and the veteran coach told l'Interista: "He was very, very agile between the posts, reactive and skilled in 1-on-1 situations, all characteristics that I still see in him as strengths today.
"What we tried to improve was the game with the feet, from below. At the time he had some things to fix in this sense, but I believe that starting from that work we did at Las Palmas and then continuing along his path, he definitely succeeded to grow and make it a strong point.
"Today he is also a goalkeeper with great intuition, intelligent and also courageous in his distribution. To get an idea of him: he was the starter and his assistant was Alvaro Valles, who has just had a great season and now Betis wants him. Already then in short he was of absolute value, a guarantee.
"It's a good move for Inter, certainly. He'll do well in Milan."