Sally Pearson has pulled out of the 100m sprint at Saturday night's Perth Track Classic, but will compete in the hurdles.
"I am being cautious with my hamstring as I have World Indoors in two weeks time and want to make sure that my body will be 100 per cent for those Championships," Pearson said.
"I will still run the hurdles (100m), and I am really looking forward to it."
Pearson's battle with new sprint queen Melissa Breen in the 100m flat was to be one of the drawcards of the event.
Breen set a new Australian woman's record for the 100m with a time of 11.11sec. earlier this month, breaking Melinda Gainsford-Taylor's 20-year-old mark.
Internationals on show at the Perth Track Classic include dual Olympic gold medallist Felix Sanchez (400m hurdles), America's 400m world champion LaShawn Merritt, mile specialist James Magut and African sprint champion Simon Magakwe.