James Lawton: Madrid to offer ultimate test of Beckham's credentials

England captain must convince doubters he is worthy of playing alongside Zidane and Ronaldo in stadium that is familiar with greatness

Now we will see how good he really is. David Beckham's move to Real Madrid puts both his fans and his sceptics on critical alert and, more vitally, demands from him the supreme effort of his freakishly lauded career.

Those who say that his reputation is a huge confection, that attributing to him anything more than specialised - and extraordinarily special - gifts is a hopelessly extravagant assessment, must be prepared to dramatically revise a view that became ever more jaundiced on his latest search for headlines. However, those others who assert his greatness, rather than his unprecedented celebrity, also have to pay close attention to events at the Bernabeu over the next few months.

The point is that no football stadium on earth is more familiar with true greatness - and it is against this glorious reality that Beckham must show that Sir Alex Ferguson was wrong to assign him to the margins of Manchester United's Premiership-winning team.

That is one basic challenge for the pin-up boy of the world game. Another is Real's own candour about the motivation behind their £25m purchase. They have made it clear enough that if football value and the strengthening of a team betrayed by defensive frailty were the only factors players such as Arsenal's Patrick Vieira and Milan's Alessandro Nesta would have been gathered in with far more enthusiasm - and greater expense.

But Real have put a value on Beckham's celebrity, seen him as someone with the image to extend their brand value into the huge Far Eastern market. This will cause little excitement on the vast terracing of the Bernabeu. There the demand of the aficionados will be simple enough. It will be for signs of greatness, for real achievement behind all the media obsession.

Despite the demands of public relations, we can also be sure that judgement in the Real dressing room will also be down to the reality of Beckham's performance - and certainly it will not have gone unnoticed there that he was so ineffective in the first leg of the Champions' League quarter-final between Real and United, Ferguson was provoked to make clear his belief that it was time to part.

In that harsh light, comparisons will inevitably be made between Beckham's achievements and those of the reigning Real stars.

Can Beckham's form begin to measure itself against that of Zinedine Zidane, winner of a World Cup and European championship for France and the European Cup for Real - with a goal that was promptly placed among the greatest of all time? Or that of Ronaldo, who brought Old Trafford to its feet in one of the greatest spontaneous shows of respect ever seen and heard at the Theatre of Dreams? Ronaldo came as near to winning a World Cup single-handedly as anyone since Diego Maradona. Even Luis Figo, perhaps the most vulnerable at Madrid and Beckham's direct rival, showed as recently as the United tie that his genius for scoring sublime goals is still a factor that can be applied to any individual fight for survival.

Those who see Beckham's chances of pulling his chair under the Real table as distinctly problematic, will also point out that he is leaving a zone of comfort at United. Idolised by the fans, his deficiencies of pace and tackling always compensated for by a manager conscious of his supreme ability with the deadball and brilliant consistency in providing crosses from the right, Beckham is facing new and searching demands.

For, to use a bull-fighting term, Beckham is leaving his querencia. It is that part of the ring where the bull is most dangerous and which he claims for himself. That was, surely, the role of Old Trafford through all the days of a massively hyped career.

Of course he is capable of spectacular deeds. He announced that with the virtuoso goal against Wimbledon, and there have been many others. But, it has to be said, few of them have been at the peaks of the game. Roy Keane consistently overshadowed him in European football and, when the Irishman was forced out of the European Cup final in Barcelona, Beckham's performance was less than overwhelming. He has had two poor World Cups.

These are the necessary cautions against high expectations of achievement in Madrid. Yes, he has some dazzling talent, but he has proved vulnerable to close attention from speedy defenders - and in La Liga he will meet quite a few of those.

On his behalf, it has to be said that few players can have embraced so fully a test of their destiny. His lack of enthusiasm for a move to Barcelona underlined his belief that he belongs at the top of the game, and now he has to find his way to its peak. Only the churlish would deny him credit for such nerve... or deny that it might just bring him recognition beyond any dispute.