Cristiano Ronaldo was given the footballing education of dreams during his first spell at Manchester United.While the five-time Ballon d'Or winner would have made a success of himself wherever he went during those crucial early years of his career, there's good reason to think that choosing United specifically really put him on the road to superstardom.Not only did Ronaldo benefit from having arguably the greatest manager of all time in Sir Alex Ferguson, but he also joined an elite dressing room who had won pretty much everything at the highest level.
Ronaldo and Keane at Man Utd
From Gary Neville to Ruud van Nistelrooy and Paul Scholes to Rio Ferdinand, there were plenty of key figures in the United squad that Ronaldo could learn from to help master his craft.
However, it's hard to imagine that anyone in the Red Devils set-up will have helped to drill an elite mentality into Ronaldo's head better than Roy Keane.
Arguably the greatest leader that the Premier League has ever seen, Keane always demanded the highest standards from his teammates and endured as the driving force behind so many of United's most successful ever teams.
And despite Ronaldo and Keane's paths only crossing for about two seasons at Old Trafford, one brilliant impact that we do know the United icon had upon the club's new number seven was keeping his feet firmly on the ground.
Besides, without experienced heads like Keane keeping things calm, you could certainly have forgiven Ronaldo for getting swept up in all the hype that surrounded his move to England.
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Ronaldo's iconic Man Utd debut
Nevertheless, the mature and long-term way in which Keane viewed matters was apparent from the off with the Red Devils skipper having a very - how shall we say? - typical reaction to Ronaldo's iconic debut for the club against Bolton Wanderers.
This was, after all, a first appearance so eye-catching that it even reportedly left the late, great George Best blown away by what he had seen.
According to The Sun, the United legend said of Ronaldo's bow: "Ronaldo’s first United game as a substitute in the season opener against Bolton was undoubtedly the most exciting debut performance I’ve ever seen.
“A few of my old team-mates were at the game and they compared him to me. There have been players who have some similarities, but this lad’s got more than anyone else, especially as he is genuinely two-footed.
Video: Ronaldo's electric highlights on Man Utd debut
"He can play on either wing, beat players with ease and put in dangerous crosses with his left or right peg.
"When was the last time you saw that? With Ronaldo and Giggsy on the pitch at the same time, opposition defenders will be petrified!"
"£12.4million seems a high price for an 18-year old, but I think it’s a snip. You are talking about a lad who, if he stays injury-free, has 15 years ahead of him in the game."
MANCHESTER, ENGLAND - AUGUST 16: Cristiano Ronaldo of Man Utd makes his debut during the FA Barclaycard Premiership match between Manchester United and Bolton Wanderers at Old Trafford on August 16, 2003 in Manchester, England. (Photo by Alex Livesey/Getty Images)
What did Keane say about Ronaldo's debut?
But what about Keane? Well, it's a completely different story, because footage of the Irishman being asked about Ronaldo's debut continues to fascinate for just how conservative, sensible and no doubt motivating it proved to be.
In a video taken from a review of United’s 2003/04 season which was shared around by fans again earlier this year, Keane can be seen channelling his ever-subdued sensibility by tempering the hype surrounding Ronaldo.
It really is a perfect example of the elite mentality of both the United dressing room and Keane himself at the time, so be sure to check out the timeless clip for yourself down below:
Video: Roy Keane's reaction to Ronaldo's first Man Utd debut
Keeping Ronaldo's feet on the ground
Could his answer have possibly been any more Roy Keane? Well, no, and that's what makes it wonderful.
There was so much excitement around Ronaldo at the time that it must have been invaluable for the most respected player in the dressing room to create an environment that ensured he didn't get carried away with things.
Don't get it twisted, Ronaldo is perpetually motivated to improve regardless of what people might be saying, but the brilliant example set by Keane must still have gone a long way towards keeping him humble and hungry.
LIVERPOOL, ENGLAND - FEBRUARY 19: Wayne Rooney and Roy Keane of Man Utd congratulate Cristiano Ronaldo on scoring the second goal during the FA Cup Fifth Round match between Everton and Manchester United at Goodison Park on February 19, 2005 in Liverpool, England. (Photo by Laurence Griffiths/Getty Images)
And that's a mentality that altogether encapsulates the Ferguson era at Old Trafford with star players like Keane always looking for more, always gunning for improvements.
So although some might watch back his comments and call him 'misery guts' or something to that effect, just remember that the results speak for themselves because the Ronaldo that later went onto leave United in 2009 was a superstar destined for greatness.
And there's no denying that Keane played a key role in that extraordinary rise.
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