James Lawton: Fading light of Ronaldinho and Barcelona gets Europe's big week off to gloomy start

This is the week when European football is supposed to get serious, and seriously brilliant, when the greatest players of the richest clubs justify their astonishing rewards. It is a pretty, even soaring idea but unfortunately that is all it is: an idea, a hope that becomes a little more fragile with every burst of hype. We had all of that in the World Cup last summer and how long did it last? Just the time to see Argentina were a cruel myth, the Brazilians had come along in name only, England were as bad as some feared and that cheating was still on a flood tide.

When Zinedine Zidane, who was supposed to be the redeemer, disfigured the final, it provoked, after the initial shock, not a lot more than a shrug - and a question. Who, when you came right down to it, could you trust? The same is true of this week. Can we trust Ronaldinho, the most crushing disappointment of all in the World Cup, to lift himself out of what resembles nothing more than a sulk and remind us of how it was when he was the world's best player by the length of Las Ramblas? Can we believe Samuel Eto'o, arguably the most deadly big-time striker in the game, will end his one-man insurrection before Liverpool arrive at the Nou Camp tomorrow night? And can we take Liverpool even half seriously after those pathetic shenanigans in Portugal when they were supposed to be steeling themselves for the big challenge at a warm-weather training centre?

These are questions that can be broadened in any direction you choose, but maybe it is enough to dwell on the reigning champions and those of 2005. When Liverpool beat Milan in Istanbul, they greeted the dawn as though it was a fantasy. Now, when you hear allegations that Craig Bellamy, a serial miscreant, took a golf club to his team-mate John Arne Riise because the Norwegian refused to bond with him on a karaoke stage, you have to suspect that indeed it was. However, the Liverpool manager, Rafa Benitez, lacked the resources of a Mourinho or a Ferguson and he felt he had to take the long-shot chance of Bellamy maturing to the point where he might consistently exploit his blinding speed. He took a similar risk with Jermaine Pennant, a talent who might just overcome a troubled past. He made a failed attempt to reclaim the fading skills of Robbie Fowler.

These, Rafa might have said before the arrival of big American money, are the odds you have to try to beat. How do you explain, though, the decline of Barcelona, the war between Ronaldinho and Eto'o and the freely expressed contempt for coach Frank Rijkaard? No one could say of Barça, as they did Liverpool, that they became masters of Europe by default. Though it took the superbly effective injection of Henrik Larsson to confirm the point, Barcelona were unquestionably the most creative and thrilling team in Europe when they triumphed in Paris last spring.

Yet less than a year later they are the, mostly, walking evidence that football success has probably never been more ephemeral than it is today when the players - who are supposed to shape it, and build one success upon another with discipline and understanding of what the game demands - have never been rewarded so stupendously.

Barça dismayed their admirers in Valencia on Sunday night; they were toothless until the arrival of Lionel Messi. Ronaldinho used to play with a smile on his face. Now it is more of a grimace.

Once he went to the Bernabeu with the confidence that he would conquer a hostile crowd. He was a goofy but imperiously inventive matador, mocking the clowns in the executive suite who said he wasn't sexy enough to play for Real Madrid. Real fans, sickened by the slide of their own team into the galactico morass, gave him his due.

It was a wonderful story that lost ground in the World Cup, when the old Brazilian guru Mario Zagallo complained: "When is the other Ronaldinho going to show up? You know the one I mean, the one who plays for Barcelona."

Now a terrible suspicion, one voiced here some time ago, accompanies the fading of Ronaldinho's light. It is that he has had enough of Barça and that in the summer, given some progress there in the task of putting out the fires and sweetening the air, he will be in the red and black of Silvio Berlusconi's Milan.

That would be confirmation of the bleakest kind, given the meaning of Ronaldinho's Barcelona when that light was still luminous. It would say that football has never been more transitory; that great stars no longer embrace great theatres, as Johan Cruyff once did the Nou Camp, but pass through on the best possible financial terms. This certainly is a lurking fear at Old Trafford, as the lionisation of Cristiano Ronaldo reaches the outlandish point where some are claiming he is already the best player in the Premiership and that he will inevitably finish up in Spain, possibly as Ronaldinho's successor.

That Ronaldo, as he reminded us in his eye-catching but profoundly profligate performance against Reading at the weekend, has still to engage the quest for substance over show, is not the main point here. The real one is that, in its big week, European football got off to a most underwhelming start.

Liverpool were distracted by the alleged adolescent behaviour of at least one senior player. Barcelona were the palest version of themselves as they threatened to fall apart. Real Madrid, hoping that David Beckham's parting gift might just be more satisfying than any he had offered before, saw the departing superstar caught up in peripheral nonsense that earned him his eighth red card.

So where do we find the best indicators of impressive performance? Probably in the work ethic of the Chelsea manager, Jose Mourinho, and the still powerful legacy that his Manchester United counterpart, Alex Ferguson, has bequeathed to himself. Mourinho may be in danger of losing his long battle against the star system at Stamford Bridge but, for the moment at least, his team seem to have regained much of their old fortitude. If it holds for a few months more, and delivers the European Cup, Chelsea's latest loss of £80m will no doubt be written off cheerfully enough by Roman Abramovich - and Mourinho will move on with his vanities and his foibles and his casual approach to the truth.

But then he will also take his awareness that the making of a real team, rather than a collection of celebrity players, has never been more vital than it is today. Ferguson's reassurance comes when he looks at Paul Scholes and Larsson. As much as Mourinho's implacable demands, they represent the value of staying the course.