Val Adams has pulled out of the track and field world championships in Beijing this month.
The shot putter's rehabilitation from injury has not gone well enough for her to consider an attempt at a fifth consecutive title on August 22.
The 30-year-old has not thrown beyond 18.79m in Diamond League competition this season, a distance which has left her trailing the leading exponents - Germany's Christina Schwanitz, China's Lijiao Gong and the United States' Michelle Carter - who have surpassed 20m.
"I have thought about this long and hard and know it's the right thing to do for all those that know me, know how competitive I am, and how much I love competing in the black singlet," Adams said.
"Deep down this is not easy but I'm a realist and know I'm not ready just yet and I still have stuff to work on. It's been a challenge since my surgery on my elbow, especially as it is taking more time than I thought it would... But that's life and I must roll with the punches and deal to this sucker.