His admirers say he is "the one the stars ask for". Sakari Orava, a surgeon and research director at the Mehilainen Sports Clinic in Turku on Finland's south west coast, has built up a patient list over the last 20 years which includes the top elite athletes from across Europe.

His contacts on the international sports scene come from his time as head physician for the Finnish Olympic team between 1988 and 2000, which took him to Seoul, Barcelona, Atlanta and Sydney. He has made a special study of hamstring and Achilles tendon injuries and has built up unrivalled experience in their repair. He has published 104 papers on his research in well-regarded scientific journals.

In an interview with a Spanish magazine last year, he described how at the 2000 Sydney Games he demanded to operate on a Finnish Olympic team athlete while serving as the team doctor, and was almost rebuffed by the host nation.

The Finnish javelin thrower Harri Haatainen had ruptured an Achilles tendon in the middle of the Games and was taken to a local hospital. Orava presented himself and said he wanted to operate on his countryman but, as a foreigner, was refused.

"I asked Haatainen's physician to check who was an expert on the Achilles tendon on the internet, he said. The physician evidently came across Orava's name in his search. "Afterwards he came to me and said it would be an honour if I would participate," the surgeon said.

He has maintained offices in Spain and Italy since the 1980s and has treated a succession of international footballers. One of his most challenging cases was the FC Barcelona midfielder Josep Guardiola, who now coaches the team.

Guardiola, then the Barcelona captain, had torn his hamstring many times. Dr Orava was summoned to help and performed the repair under the gaze of a number of specialists keen to learn his technique. The recovery of the Spanish player was followed minutely by the media over the following days.

Achilles tendon injuries remain one of his special interests along with other muscle, foot and tendon problems.

But like his illustrious British patient David Beckham, Dr Orava is approaching the end of his career. In an interview last year, he said he intended to reduce his workload. "I am going to work here in Mehilainen for a while still, whatever that means. I am going to have to slow the pace down and move on to being a consultant, advising the younger ones," he said.

Professor Angus Wallace, an orthopaedic surgeon at the University of Nottingham and a specialist in sports injuries, said: "Sakari Orava and his team have done a lot of research on the repair of tendon injuries using minimally invasive methods and they have a very good record."

Professor Wallace said he did not believe that Beckham would recover in time to play for England in the World Cup. But he said the midfielder was a "driven individual" who was "absolutely dedicated" to his country and his football. Although he believed there was a less than a 1 per cent chance of him making it to the tournament, he added: "With Beckham you can never say never."