EASTBOURNE, UK - World No.1 Ashleigh Barty has announced her withdrawal from this week's Nature Valley International with a right arm injury.

The Australian, fresh off winning the Nature Valley Classic title in Birmingham last week, who had been the No.1 seed in the draw, told press: "It's an injury that we've had to manage since I was 16 years old. When I have a spike in load it comes up - it's a bone stress injury and I need to look after it, particularly in these first few days. We know how to manage it but it's important to get on top of it straight away.

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"I think we'll be fine for Wimbledon, we just need to make sure that we manage it correctly over the next three to four days to make sure that I'm fully healthy next week.

"It's rest, it's time off court, it's also carefully monitoring how many balls I hit when I do get back on court, particularly with serving. It's an injury I've had since I was 16 years old and at certain times of year I need to be more careful with it.

"It's very similar [to my withdrawal from Strasbourg] - when I have a very heavy week, it's just making sure I do all the right things to let it settle and then build it back up again to be ready to play."

On Barty's first day at the top spot of the WTA rankings, the 23-year-old was sanguine about the pressure of maintaining her place. "I guess we'll wait and see," she said. "I haven't played a tournament yet, I haven't played a match. I'll continue to try and go about my work the same way and see how it goes."

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With the prospect of walking on to court at Wimbledon as the top seed, Barty said that she did not know how she would deal with the pressure. "I don't know, I've never done it before!" she laughed. "But it's an exciting challenge."