Then there is Marion Jones, winner of the world title in Edmonton in 2001. Her fading form these past two summers has coincided with her unproven implication in the Bay Area Laboratory Co-Operative – Balco – drugs scandal.Felix has long been labelled “the new Marion Jones”. Two years ago she broke Jones’ US junior and high school records with a time of 22.51sec at the Mount Sac Relays in California. At the same meeting 12 months previously she had queued for Jones to sign her autograph book.The prospect of Jones ever having to testify in court against accusations that she used banned performance-enhancing drugs faded last month after the final defendant in the Balco case, Dwain Chambers’ former coach Remy Korchemny, agreed a deal with the prosecuting authorities in the United States.”I really haven’t been following it,” Felix said, with not a little exasperation, when asked about the Balco saga and the cloud that has been cast over Jones and US sprinting. “I’ve been out there training and just focusing on me and the World Championships. I haven’t had to deal with any of that.”Felix has been doing her training in Los Angeles under the guidance of Bob Kersee, husband of the heptathlon world record holder Jackie Joyner-Kersee and brother-in-law of the late Florence Griffith-Joyner, who put the world 100m and 200m records beyond the grasp of her rivals and succeeding generations with the finger of suspicion being pointed in her direction (without any firm foundation, it has to be said).Not that Felix can remember any of the fuss about Flo-Jo.

She was, after all, only two when Griffith-Joyner scorched to the Olympic 200m title in a freakish 21.34sec in Seoul in 1988.. It is important to observe that you do not become a bad player overnight. In Michael Vaughan’s case the decline has been steady for almost two years, and it is now starting to gain a worrying momentum. England’s captain is slipping down the charts quicker than a boy band’s single. How long ago it seems since Sydney in the early part of 2003. He had scored a coruscating 193 against Australia in the final Test, he was the player of the series and he was ranked as the No 1 batsman in the world.

Think of it: an Englishman in a heavily beaten team still trying to find their way, and he was the best batsman on the planet It was a status he deserved, too He was rigorous in method, straight, orthodox and elegant.

His cover drive was as beautiful as it was effective.But yesterday at Edgbaston, Vaughan’s form appeared to have reached a nadir He was castled by Brett Lee. The ball was fast and straight, as you would expect, but Vaughan was going nowhere in addressing it. Before this match he had slipped to No 28 in the world rankings, and he could now be out of the top 30.There was hardly a single decent aspect about the shot to the ball that bowled him yesterday. He began with a forward press, then became stuck in the crease, as if half-expecting low bounce. To compound everything he brought his bat down crookedly and the ball burst through that creakily constructed defence.

You could over-analyse it, but you did not need to have the most rudimentary coaching badge to realise that the shot was just plain bloody awful, and if the ball kept a tad low it was all he deserved for playing it like that.It was a bad way to go and it was a bad moment for England. Vaughan has never been the player he was in Australia since he became captain three Test matches later. He is not the first captain whose form has been brought low by the cares of leadership, and nor is he the first to deny it.Indeed, Vaughan has said time and again that his form has held up pretty well, and when pressed will say that he has averaged 40 as captain. This sounds pretty good, and the spiral has not all been downward. But in 52 innings as captain his batting average is 35.53, just about on the correct side of acceptable.

Take matches against Bangladesh out of that equation and it slips to 30.83, the wrong side of acceptability.There is no easy way round this Being captain of England is a tough job. Vaughan, who has a wonderfully impressive sense of perspective, is nonchalantly categoric in insisting that plenty of people do jobs that are more significant.He would seem to have an ideal temperament for the rigours of office. He is not a heart-on-sleeve merchant as was his predecessor, Nasser Hussain, he is not as plainly relaxed in approach as was, say, David Gower There is little that is emotive about Vaughan. When he speaks to the press, even before this Ashes series, the biggest of his life, perhaps especially before this Ashes series, he might as well be dictating a shopping list.But it is affecting him. How otherwise to explain the dip that, in truth, is becoming something akin to the Grand Canyon Maybe it would help if Vaughan conceded the point.