Leonardo brought Marco Verratti to Paris Saint-Germain as a relatively unknown talent and now believes the Italy international has developed into one of the world's best midfielders.
Verratti, 23, joined PSG in the summer of 2012, with his arrival in the French capital from Pescara overshadowed by the unveiling of Zlatan Ibrahimovic on the same day.
Since then, however, Verratti has made a real name for himself at the Parc des Princes, playing a central role in the club's four successive Ligue 1 title wins.
As PSG's sporting director at the time, Leonardo orchestrated Verratti's transfer, and he has told Cadena Ser the player will soon be as important for his country as he is for his club.
"Marco is an incredible player with a great personality, incredible technique and just a crazy touch. He tries mad things to convince himself he's able to do them," the former AC Milan and Inter Milan coach said.
"In his first season, he tried dribbling just outside his own penalty area. We all went mad because he took big risks in key areas of the pitch, but he's shown that that is how he plays. Everyone loves him, in a team of great players. He holds the keys to Paris Saint-Germain's midfield now, and it'll soon be the same for Italy."