Former Juventus manager Massimiliano Allegri believes Cristiano Ronaldo's mentality is one of the key reasons why he has enjoyed so much success in his career.
Ronaldo, 34, has enjoyed a glittering career which has seen him win three Premier League titles with Manchester United , four Champions League crowns with Real Madrid and the Euro 2016 trophy with Portugal.
It was at Madrid where he arguably enjoyed the most success but he brought an end to his trophy-laden nine-year spell in Spain to join Juventus last season.
Allegri was in charge of Juve last season as five-time Ballon d'Or winner Ronaldo scored 21 Serie A goals and 28 in all competitions to help the Italians secure their eighth consecutive Scudetto.
And the Italian coach, who is currently without a job after quitting the Turin club in the summer, has revealed what makes Ronaldo different to other players he has coached.
"His strength is on a mental level," said Allegri. "He is 34 years old, he has won championships, European titles and golden balls but he continues to give himself important stimuli that make the difference.
"The technique is fundamental to stay at high levels for many years, but the difference is made by the head and the professionalism. If I prefer to coach Ronaldo or a young talent? Ronaldo, without a doubt."
The manager, who was replaced at Juve by former Chelsea boss Maurizio Sarri, also insisted that he has no regrets over parting ways with the European giants.
Allegri added: "I have absolutely not regretted the choice made with Juventus, things must not be forced.
"After five years it was time to take a break, perhaps the president had understood it before me."
Meanwhile Ronaldo returned from international duty with Portugal this week to launch his new CR7 Play It Cool fragance.
The Portuguese superstar attended a launch party in Turin, where spoke to Piers Morgan in a wide-ranging interview that is due to be aired next week.
And the 34-year-old appeared in high spirits as he posed for snaps with Morgan and his partner Georgina Rodriguez.
