It would have been impossible to predict Ronaldo would accomplish everything he has, but the mentality was there from the very beginning.

“I remember us being ready to step on to the pitch to face Manchester United [in the 2003 friendly at Alvalade], with both teams lined up side by side – United with big names like [Ryan] Giggs, Paul Scholes, and [Ruud] Van Nistelrooy,” Joao Aroso, who was Sporting fitness coach back then, told BBC Sport.

“And you’d expect Cristiano, an 18-year-old at the time, to look at them, at such famous players. But I remember looking at Cristiano and seeing him completely focused on the game, not distracted at all – he didn’t even glance at them.

“That says a lot about his personality.”

Ronaldo would go from there to United, then to Real Madrid and finally to Juventus, winning five Ballons d’Or and becoming arguably Portugal’s greatest-ever player along the way.

Former Manchester United performance coach Mick Clegg, told BBC Radio 5 Live’s Football Daily: “I have looked at loads of great people since working with Ronaldo and I think Cristiano Ronaldo is in the league of Leonardo da Vinci, Albert Einstein, Isaac Newton, Nikola Tesler and Stephen Hawking. And what are they? They are all geniuses and he is a genius.

“In the first session in the gym when he came to United he said ‘I am going to be the best player in the world’, and it was quite startling. He is unique.

“His plan was to get every bit of information out of those who were going to coach him and challenge them. His whole mind is about creating something great.

“Cristiano is only made of blood and bone. Is it possible there are more people like him? I just hoped someone would come along with anything like he has but they are so remote.”

Ronaldo has been involved in more than 30% of the matches ever played by the national team. But more importantly, he’s changed the perception around a team that had always been known for an inferiority complex that held them back in the past.

“Cristiano is one of a kind,” said Aroso, who also worked with the forward as a Portugal assistant coach and is currently part of the South Korea national team staff.

“He’s defined a style, in every way, with his relentless ambition to break records and the age to which he continues to play. Just as Maradona was unique, as Pele was unique, as [Lionel] Messi is unique, Cristiano is too, for his own reasons.

“What I want to highlight is that for Portugal, having a player like Cristiano is extremely important. We are a small country that rarely has a global impact outside of football.

“He allows our small country to be known worldwide for something great – because of Cristiano and all the positive things he stands for.”

There doesn’t seem to be much doubt that – as long as Euro 2016 winners Portugal qualify – he will be at the 2026 World Cup. The real question mark is whether he can make it to 2030, when the country will co-host it.

“I have no doubt [that he can do it]. He’ll go on another diet and be there, nice and slim,” former winger Nani said with a smile.