Stress fracture rules Laura Robson out of training camp

British number four Laura Robson has been forced to cancel a training trip to Las Vegas after suffering a stress fracture of the left shin.

The 17-year-old was due to spend three weeks at a camp with Andy Murray's occasional coach Darren Cahill and Andre Agassi's ex-trainer Gil Reyes.

However, Robson has targeted January's Australian Open for her comeback.

"I'm unable to go to Vegas but back in action in a few weeks so prep for Aus will start then," she said on Twitter  .

A hip injury ruled the Australian-born left-hander out for the early part of 2011 but she reached the second round of the final two Grand Slams, Wimbledon and the US Open.

She beat British number three Heather Watson last month  and has risen to a career-high of 131 in the WTA rankings  .