Injured Del Potro out of Vienna tennis reckoning

Juan Martin Del Potro withdrew from the Austrian Open on Thursday, suffering from an injury to his right toe.

The 20-year old from Argentina, who is seeded three, was due to play Germany's Philipp Kohlschrieber.

The injury has dealt a blow to his hopes of qualifying for the Masters Cup to be held next month in Shanghai, and comes during his first week ranked in the world's top 10.

Ranked 75 in April, Del Potro has become been one of the hottest players on the ATP Tour. Beginning in July, he has won 30 of 32 matches, playing five finals and claiming four titles.

Last week he reached the final in Tokyo, but was hindered by an upset stomach as he fell to Tomas Berdych.

His win on Wednesday over Austria's Martin Fischer lifted him above James Blake into eighth position in the Race To Shanghai, but at the beginning of this week less than 100 points separated Blake and 22nd-placed Radek Stepanek.

There are just three weeks of the regular season to play, and Del Potro will hope that he will be fit to contest the Masters events in Madrid and Paris in a bid to solidify his position.