Australian Olympic hurdles champion Sally Pearson said Monday she needs further wrist surgery, ruling her out of the Beijing World Athletics Championships in August.

Pearson injured her left wrist when she tumbled during a Diamond League race in Rome earlier this month and the 28-year-old will have more surgery on Tuesday.

Doctors described the injury as a severe "bone explosion" and have put no time frame on her recovery. Pearson said her fall was caused by a minor tear in a calf muscle with scans to determine the full extent of that damage.