Andy Murray today insisted he would prove his mum wrong by launching a concerted double assault on both the Olympic and US Open tennis titles.

Judy Murray is concerned her younger son will be damaging his chances of winning the US Open - the tournament Andy has always seen as his best bet for a Grand Slam triumph - so soon after attempting to win both the singles and doubles titles here in Beijing.

But on being told of mum's worries today, Murray said: "I think she's wrong. I believe you can do well in both tournaments."

The men's tennis begins on Sunday and Murray, fresh from winning his first Masters Series tournament, admits he will have a demanding schedule since he's also contesting the doubles with brother Jamie. The US Open starts at Flushing Meadows eight days after the final.

"It does make it harder if you do well here but there are three weeks between both finals and you're going to have at least two weeks off during that time because you're only playing every second day in the Slam. If you do all the right things in between the tournaments you can do well in both," said Murray.

Murray says the experience of Village life has been "awesome" but some tennis stars, such as Roger Federer, have chosen to stay in hotels, which has only heightened the idea that those who treat Grand Slams as being far more important then the Olympics don't belong in the Games.

Murray, who is set to start his campaign on Monday against Taipei's Lu Yen-Hsun, defended the sport's place in the programme, saying: "If there came a stage when seven of the top players weren't competing you could say it wasn't too important but winning the gold is huge. That's why the top guys are here."

There was good news for Federer, with big-serving Croat Ivo Karlovic, who ended his reign as world No1 by beating him in Cincinnati last week, having to withdraw through injury. The pair were due to meet in round three.

Injury has also affected the women's tournament, with Lindsay Davenport pulling out of the singles because of a knee problem.

Davenport, who won the gold medal at the Atlanta Games in 1996, is still expected to compete in the doubles with Liezel Huber.