Del Potro moves within striking range of Murray

On Sunday, the Argentine big-hitter plays his British rival in London, and could soon overtake him in the rankings. He tells Paul Newman about their rivalry

If Juan Martin del Potro fails to reach the final of the Barclays ATP World Tour Finals at London's O2 Arena a week on Sunday it will at least give him a chance to catch up with friends. The 21-year-old Argentine is on good terms with many of his country's leading footballers and it will not have escaped his attention that Liverpool, the club of Javier Mascherano and Emiliano Insua, meet Everton that day.

Manchester City's Carlos Tevez is another fellow countryman he is aiming to meet over the next week. "I'm hoping he is coming to London to watch me and I am hoping to watch him," Del Potro said.

Del Potro, who also keeps in touch with Lionel Messi, Sergio Aguero, Mauro Camoranesi and Lucho Gonzalez, was no mean footballer himself. "I love soccer, but I never thought seriously about being a professional," he said. "There's a big difference between players like them and me. When I was young I was good at it, but now I can't move. I can't run for 90 minutes."

The world No 5 is being unduly modest. When he won his first Grand Slam title at the US Open two months ago Del Potro was still going strong at the end of a four-hour final, having come back from two sets to one down to beat Roger Federer.

Sport is in Del Potro's blood, though he says he did not follow the example of his father, who played rugby semi-professionally, "because I don't have the muscles". Argentinians excel at a wide range of sports. Charlie Epps, an American golf coach who worked with Angel Cabrera and has been visiting Argentina for many years, puts the country's success down to "meat and potatoes". Del Potro, who adds wine to the list, agrees the diet is important, although there is another major local factor in his own success.

He comes from Tandil, 150 miles from Buenos Aires. Remarkably, five other tour players have emerged in recent times from the mountain city, which has a population of about 100,000: Juan Monaco, Mariano Zabaleta, Maximo Gonzalez, Diego Junqueira and Guillermo Perez-Roldan.

All were coached by Marcelo Gomez, of the city's Independiente club. Del Potro says the secret of the coach's success is that he keeps the game simple. "He is very good with young ones and if you go to see him you will end up playing good tennis for sure," he said. "When I was young I travelled with him and he was like another father to me. That's very important when you are young. My parents are friends with him and I still speak to him every day. He's a very good person. I spoke to him before the US Open final."

Del Potro, who now works with another coach, Franco Davin, was given a hero's welcome when he returned to Tandil after his triumph at Flushing Meadows. "I was driven around the city on top of a fire engine," he said. "It was scary, but it was also the best moment of my life. Everyone came out on to the streets and I felt very happy. I feel very happy whenever I go back to Tandil. It's very important to me."

In April last year, Del Potro was ranked 81 in the world, but he won four tournaments in succession in the summer and by October had broken into the top 10. He made his debut in the season-ending championships last year but did not go beyond the round-robin stage.

This year he has made further progress and is now fewer than 700 points behind Andy Murray in the world rankings. With plenty at stake in London – an undefeated champion would earn 1,500 ranking points – Del Potro could yet replace Murray as world No 4 in the year-end standings.

The Argentinian could prove to be a thorn in Murray's side for years to come. Sixteen months younger than the Scot (whom he meets in the opening singles match on Sunday), he has already beaten him to a first Grand Slam title, although Murray has won three of their four meetings.

Although there is not a great deal of subtlety to Del Potro's game, he has been working hard in the gym and on his serve and forehand, ensuring that he makes full use of his 6ft 6in frame and huge wingspan. In the US Open final, Federer came under increasing pressure from the huge ground strokes Del Potro was clubbing from behind the baseline.

Nevertheless, New York appeared to take a lot out of the Argentinian, who has won only two matches since, retiring mid-tournament from the Shanghai and Paris Masters with wrist and stomach problems. He insists he is fit again, but is cautious about his chances in London. "The favourites are still the same – Federer, Nadal, Djokovic, Murray. I need to get more experience. I have to learn much to be like them."

Del Potro is at his best on hard courts, and in three visits to Wimbledon he has failed to go beyond the second round. "I don't play good tennis there, but I will learn because I love Wimbledon," he said. "I'd like to play good tennis on grass. It's difficult, but if Ivanisevic and Safin can play on it, maybe I can too."

Tall order: Giants on the court

Modern-day tennis players are getting bigger. When Juan Martin del Potro met Marin Cilic in the US Open quarter-finals in September they equalled the record for the combined average height of two men playing at that stage of a Grand Slam tournament in the Open era. Both men are 6ft 6in tall. Alexander Popp (6ft 7in) and Mark Philippoussis (6ft 5in), who met at Wimbledon in 2003, share the record.

Current giants on the Tour...

Ivo Karlovic 6ft 10in

John Isner 6ft 9in

Marcelo Melo 6ft 8in

Kevin Anderson 6ft 7in

Chris Guccione 6ft 7in

... and giants of the past

Milan Srejber 6ft 8in

Victor Amaya 6ft 7in

Alexander Popp 6ft 7in

Marc Rosset 6ft 7in

Paul Newman

ATP Finals: The line-up

Sunday Afternoon D Nestor/N Zimonjic v M Fystenberg/M Matkowski; A Murray v J M Del Potro.

Sunday Evening M Bhupathi/M Knowles v F Cermak/M Mertinak; R Federer v F Verdasco.

Monday Afternoon B Bryan/M Bryan v M Mirnyi/A Ram; R Nadal v R Soderling. Evening: L Dlouhy/L Paes v L Kubot/O Marach; N Djokovic v N Davydenko.