Shanghai - Andy Roddick withdrew from the Masters Cup shortly before his match on Wednesday, citing a right ankle injury he suffered during training the day before.

The American, who lost his opening match to Andy Murray, will be replaced in the Red group by Czech Radek Stepanek.

The American dropped his bombshell a few hours before he was due to take to the court against Roger Federer.

"In practise I just went over on it, we tried as much as we could to get it better," he said. "I can't really stop and start very quickly. It's anything when I go kind of over on the outside it hurts.

Shanghai - Andy Roddick withdrew form the Masters Cup shortly before his match on Wednesday, with his place taken by Radek Stepanek.

Shanghai - Juan Del Potro didn't allow his mind to stray to the upcoming Davis Cup final as he handed Frenchman Jo-Wilfried Tsonga a 7-6 (7-4), 7-6 (7-5) Gold group defeat at the Masters Cup on Tuesday.

The clash between the pair of 2008 breakthrough rookies at the season-ending championships gave the Argentine a 1-1 record and saddled Australian Open finalist Tsonga from France with two defeats from as many matches.

"I'm in the Masters Cup, I want to be alive until the finals, if I can," Del Potro said.

Shanghai - Juan Del Potro kept his hopes alive for an extended stay at the M

Shanghai - Proud Roger Federer has pronounced himself massively dissatisfied with his current label of "second best" in tennis after losing the number one ranking last August to Rafael Nadal.

Shanghai - Roger Federer went through what has become his annual sponsor obligation as he taught a group of Chinese teenagers how to shave at a public relations event as the countdown continued on Friday to the Masters Cup.

The Swiss top seed - number one Rafael Nadal is missing with right knee tendinitis - will open his title defence on Monday against France's Gilles Simon.

Federer showed quick hands off the court as he brandished a microphone in one fist and a razor in the other during the "first shave" with a group of local 18-year-olds.