Beware Juan Martin Del Potro, the big friendly giant

If appearances can be deceiving, look no further than Juan Martin Del Potro. The 6ft 6in Argentine, dubbed the Tower of Tandil, cuts a fearsome figure on court and along the corridor, and is generally not the sort of person you'd want to go about upsetting.

But his imposing physique belies a soft character, a gentle giant who simply wants to succeed at what he does best.

Two years ago at Wimbledon, there was some kerfuffle when Del Potro apparently threw his shoes into the crowd in disgust at his match being called for light. Not so. When asked about it in press the next day, the Argentine revealed that he had wanted to give the crowd a thank you for staying so late to watch him, and was perfectly happy to pad back to the locker room in just his socks.

"I think the crowd was, until the last point with cold, windy, rain, so was a good idea for them," he explained. "After the match, I saw the kid with my shoes and I sign for him."

But the kindly nature of the 24-year-old's character should not fool any opponent into thinking he won't hit shots till he drops. Having hyper-extended his knee during his third round match, when he fell on it again in the early stages of his quarter-final against David Ferrer, it looked like it could be curtains. But not for Del Potro.

"I don't try to be a spectacular fall, but was really painful for me.  I was scared because I did the same thing four days ago.  I know how tough is play with some pains on the knee," Del Potro said.

"To be honest, I don't want to retire in quarters for first time at the Wimbledon against David Ferrer," he continued. "And that's the reason for continuing play.  The doctors give me good anti-inflammatories. Then I play confidence, be careful all the time with my movements.  But in the end I did 100% and I'm so glad to go through."

On Friday afternoon he will contend his first Wimbledon semi-final, his first Grand Slam semi-final since winning the US Open in 2009, and only his third major semi-final overall, the first coming at the 2009 French Open.

The waning of Roger Federer and Rafael Nadal has lead naturally to the assumption of the top of the game's reigns by Novak Djokovic and Andy Murray. But it's easy to forget that it was Del Potro who broke up the remarkable three-sided dominance of Federer, Nadal and Djokovic, the only man to win a Grand Slam outside of the big three between Marat Safin's Australian Open win in 2005 and Andy Murray's US Open win in 2012. 

But Del Potro doesn't compare himself to then. " I don't remember.  It's four years ago," he said, simply.

There's no doubt he's a better grass-court player than he was four years ago. His bludgeoning forehand can be un-gettable on this surface, and, with the confidence of an Olympic bronze medal sitting at home in Tandil, he poses a very real threat to 2011 champion Novak Djokovic. Even more so given that it was Djokovic whom he beat to win that bronze.

Djokovic's experience at this stage of a Grand Slam is leagues ahead, Friday afternoon marking his 13th consecutive Grand Slam semi-final, but he will not doubt the threat that Del Potro poses.

The Serb's court coverage and powers of recovery, turning defence into attack, have become the most impressive and astonishing part of his game, the positions he contorts his body into only truly appreciable when you look at the photographs. But if the Argentine can get into his rhythm and start swinging, it could make for a very interesting afternoon indeed.

"I will be exciting to play against him.  I remember the match during the Olympic last year on the same surface," the 24-year-old said.

"But this time the pression is different, I know.  I know it.  But I will try to be ready and do my best."

Will Del Potro's best be enough? He needs to believe that it is. 

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