Del Potro puzzled but pleased over his London semi-final status

Nov 27, 2009, 16:20 GMT

London - Juan Del Potro shook off the the remainder of his confusion over a last-gasp qualification for the semi-finals of the ATP World Tour Finals with a late-afternoon practise session Friday to prepare for a weekend shot at the year-end title.

The Argentine who repeated his victory from the US Open over Roger Federer in the pair's concluding Group A match Thursday night, had trouble puzzling out a confusing scenario which has drawn fire for the complicated and shambolic way that the two winners from the group were finally chosen.

It all came down to winning game percentage, a stat which left Andy Murray out in the cold by a hair and the Scot tweeting from his hotel asking exactly what was going in in the chaotic post-match minutes.

If he's to progress any farther, Del Potro will have to control the nerves which undoubtably arose after he had to wait for nearly half an hour to find out his qualifying fate.

'(Coach) Franco (Davin) told me I qualified after like 25 minutes after the match, nobody knows what happen,' said the Argentine US Open champion. 'But, I qualified.'

'It was very strange, but I didn't want to talk about that because the people who has to made the numbers to see who qualified...Now is the past, I'm in the semi-finals and I'm happy for that.'

Federer was sorry to have lost again but gave the South American full credit.

'I thought he played a really good match. He was able to lift his game after the first two matches where I just thought he looked a bit weary.

'For me it's a tough loss. But I'm happy I'm through. I was in a way surprised myself it came down to a couple games.

'There are certain rules and these are the rules, sometimes unfortunate, sometimes fortunate,' said the Swiss.

'How can we imagine that we all play three sets and it comes down to a couple of games. I definitely tried to push myself to close out matches as quickly as I can against fellow rivals because you never know when you might need those games.

'They might come back in the match and turn the match around completely.'

Del Potro agreed: 'This is the sport, just two players can qualify. Maybe for the local public is bad to not have the opportunity to see Murray in the semis, but they will see Federer, for sure, and another good players.'

The Argentine said that it's impossible to look too far ahead past his Saturday match.

'All players are playing very good this season, they are very strong. Djokovic for me could be the most dangerous. But Robin has a good serve.

'Davydenko is so fast. Everyone has good things to play against me, but I will try to play like today.'