Former Manchester United assistant coach Mike Phelan says Cristiano Ronaldo took Sir Alex Ferguson's management to a new level.
Phelan worked with Ronaldo during his two spells at Old Trafford.
The Portugal captain is now blazing a trail at Al-Nassr in Saudi Arabia and Phelan told Sky Sports: "He's still playing international football, yes he's in Saudi Arabia, but he's still playing and scoring goals.
"He is doing all the things we knew he could do at Manchester United.
"But a really good personality, hard-working and challenging. He challenged me as a coach, Carlos Queiroz as a coach and Sir Alex as a manager. But that's good because it takes you to another level."