Del Potro books London berth

Juan Martin del Potro has become the latest player to qualify for the Barclays ATP World Tour Finals in London.

Rafael Nadal's withdrawal due to a knee injury means Del Potro will take his place in the season-ending event at the O2 Arena.

Del Potro, who made the final on his last appearance in the tournament back in 2009, joins Novak Djokovic, Roger Federer, Andy Murray, David Ferrer and Tomas Berdych in the field.

Two places remain up for grabs with Jo-Wilfried Tsonga and Janko Tipsarevic currently leading the charge.

The Argentine said: "For me it's a gift for my effort during the year.

"Being in that tournament means a lot. It's only eight players fighting for one tournament. It's the best eight players of the year, so it's very important to me.

"I'm so glad to be there once again. I will be fighting against the big names in London and maybe I'll have a chance to make another final."

Del Potro is likely to be a serious contender given his good form indoors.

The former US Open champion won in Vienna last week and this week is through to the latter stages of the event in Basel.

The London tournament takes place from November 5-12.