Fit-again Del Potro ready to scale the heights once more

Former US Open champion in fine fettle, he tells Paul Newman

Juan Martin del Potro forced his way into the game's elite in 2009 (AP)

Juan Martin del Potro has never gone beyond the fourth round at Wimbledon, but as the 23-year-old Argentine prepares for this year's championships he knows the tournament will mark a significant milestone. It was here, 12 months ago, that he finally put behind him a year and a half of pain and doubt as he picked up the pieces of a career threatened by injury.

When Del Potro won the US Open in 2009 he appeared to have made the biggest breakthrough that any player can achieve in the modern men's game. Since the 2005 Australian Open there have been 29 Grand Slam tournaments and in that time Del Potro is the only player who has won a men's title other than Roger Federer, Rafael Nadal or Novak Djokovic.

Within months, however, the gentle giant from Tandil was wondering whether he would ever play again. A wrist injury forced Del Potro to take a break from the game and as doctors struggled to cure the problem the Argentine grew increasingly concerned about his future. After months of anguish he finally had an operation, but between January 2010 and the start of last year he was able to play only two matches.

Even when he made a successful comeback at the start of 2011, winning minor tournaments in Delray Beach and Estoril, Del Potro still suffered occasional pain and wondered whether his recovery would ever be complete. He admitted that it was not until Wimbledon last year – when he lost in the fourth round to Nadal in a near four-hour match – that the doubts finally went away.

"It took a long time," Del Potro said. "I'd been playing on clay and hard courts and I felt OK. At Wimbledon I said to myself: 'OK, I'm not scared any more.' After Wimbledon I felt like I had made my comeback."

Today Del Potro is back up to No 9 in the world rankings, though his attempt to reclaim his former heights – his highest position was No 4 – remains a major battle. Having returned to the top 20 within six months of falling to No 485 in the rankings, he has found the remaining rungs of the ladder harder to climb.

"At first when I was injured I thought I would never play tennis again," he said. "When I started my comeback I remember playing in Sydney and losing to [Florian] Mayer in the second round. I thought to myself that I was very far away from getting back to my best level, but then I kept improving, kept winning and I said I would be back in the top 100 very soon, maybe the top 50. At first my comeback was really quick. It was amazing and more than I had expected after what had happened in the last year.

"But I was watching the top-20 players and they were playing at a high level, much better than me, and I didn't know if I could get to that level. But my coach, my friends and my family gave me confidence to work hard, to improve and after Wimbledon I said: 'OK, I will be there. I don't know when, but my game is starting to be dangerous for other players again'."

Nevertheless, last year's American hard-court season, a profitable period for the Argentine in the past, was a struggle. Del Potro admitted: "The next step was difficult – from top 20 to top 15, from 15 to top 10 – because the players at the top are playing really well. And now I still feel there is a bit of a gap between me and them."

Earlier this month, nevertheless, Del Potro produced his best Grand Slam performances since starting his comeback. Having beaten Tomas Berdych in the fourth round of the French Open, he won the first two sets against Federer in the quarter-finals, only to suffer a recurring knee problem which ended his chances.

Does Del Potro think he would have won more Grand Slam titles but for his year out of the game? "Maybe the Australian Open in 2010, because I had a good road to the semi-finals," he said. "I lost in five sets against [Marin] Cilic in the fourth round, but my wrist was really painful and I lost my chance. I still dream of being world No 1 one day. I'm getting closer, but I don't know if I can do it, or whether I can be closer than I was in 2009 and 2010."

Does he ever think much about his 2009 US Open win, when he beat Nadal in the semi-finals and Federer in the final? "No. It will be there in my memory for ever and when I walk down the street people still say: 'I watched your match.'

"But now I'm trying to find a way to win another Grand Slam: maybe this year or next year, I don't know, but I'm not thinking any more about the US Open."

The Argentine has one constant reminder of the greatest achievement of his career so far. He has kept three of the rackets with which he won the US Open.

"I never play with them now," he said. "I travel with them to some tournaments, but I try to use different rackets because those are very special for me."

Does he feel he might want to use them again? "Just in case, yes. If I play in another Grand Slam final maybe I will use them."