The duo worked together during Sousa’s stint in the Portugal national team set up and the player-turned-manager says he was always one of kind.
“Ronaldo? For me, he is the best in the world,” Sousa told Italian daily La Gazzetta dello Sport.
“Above all for how he managed to always maintain the same continuity in doing what was necessary to win.
“When I was coaching Portugal’s U16 side, he was in the U19 team.
“As a kid he was already like this, he always knew how to recognise the road to improvement.
“His arrival gave the other clubs the courage to anticipate a process of growth and will change the mind of the players who no longer saw Italy as a priority football destination.”
Ronaldo was overlooked for the Ballon d’Or this season.
His former Real team-mate Luka Modric scooped the prestigious award.
Ronaldo’s manager at Juventus – Massimiliano Allegri – says the Portuguese will bounce back.
“It’s too bad, Ronaldo certainly deserved it with Real,” Allegri said at the Gala Sports Awards.
“Modric winning it will be a motivation.
“He’ll want to do better and win his sixth ballon d’or with Juventus next year.
“CR7 is a model to all footballers.
“Even with all his success and at 33 years old he still focuses on each detail.
“His talents alone don’t account for him being on his level.
“He is a likable guy and he has joined into the group well, and raised our level of professionalism, which is always a part of Juventus.”
Ronaldo is next in action against Inter Milan on Friday.
Sousa reckons the Old Lady have the edge over their rivals.
“Juventus to win? Probably yes,” he added.
“I think Juve have never had such a strong team in terms of numbers, quality and diversity of players.
“They can change the game system when they want.
“Allegri has a great ability.
“He always keeps the fire burning and the club creates the balance that makes everyone go in the same direction.”