Lionel Messi has been voted FIFA’s world player of the year for the past four season. But there is no doubt in my mind that Cristiano Ronaldo is even more valuable to Real Madrid than the little Argentinian is to Barcelona. How Manchester United deal with their former idol will determine the outcome of Tuesday night’s Champions League decider at Old Trafford.

On the evidence of the first match in the Bernabeu, there is one man who stands head and shoulders above the rest of his team. And that tells you how good he is, because Real Madrid are one of the strongest sides on the planet.

The truth is that Ronaldo is an even better player now than he was when he left Manchester shortly after being recognised as the best player in the world when he received his one and only Ballon d’Or to date.

It is baffling that the Madrid fans have not always shown Portugal’s finest the love and respect he deserves, despite averaging more than a goal-a-game since he signed in 2009 for £80m. United fans would take him back in an instant and he is still adored in Manchester which makes his return to Old Trafford the most eagerly awaited football match at the Theatre of Dreams for many years.

Robin van Persie is the new talisman in Sir Alex Ferguson’s current squad and at times this season the inspirational summer signing from Arsenal has been out of this world. Many have billed this tie as a head-to-head between CR7 and RvP. There is every chance the Dutchman will deliver the magic that ends Jose Mourinho’s dream of making Madrid champions of Europe at Wembley in May. But there is a big difference in my mind between the pivotal roles of these opposing superstars.

Ronaldo is the one player in Madrid’s star studded team who could genuinely rip United to pieces almost single-handedly. He is that good and that important to the Spanish hopes of success in the biggest club competition in world football. Stop Ronaldo and United will fancy their chances of reaching the quarter-finals. That is why Mourinho left him out of the first half of  today’s La Liga clash with Barcelona.But Real still conquered Barca and Messi for the second time in five days. That tells you all you need to know about the challenge facing United.

Van Persie on the other hand is brilliant and has stepped up another level since he arrived in Manchester in the summer. But the strength of this United side is far greater than one man and it is the unity and dynamics of the team that makes Fergie’s side special. Wayne Rooney still has the ability to terrorise opposition. Michael Carrick is playing the best football of his career. Rafael is getting better with every game. While anyone who writes off Ryan Giggs had better beware. Giggsy is destined to make his 1,000 career appearance against Madrid.And wouldn’t it be just priceless if the Welsh wizard stole the limelight.