Sally Pearson withdraws from Rio Olympics

Olympic champion Sally Pearson has withdrawn from the Rio Games because of a hamstring injury.

Pearson, who won gold for Australia in the 100m hurdles in London four years ago and was a silver medallist at Beijing in 2008, injured a hamstring while training on the Gold Coast.

"I'm disappointed  I'm gutted," said Pearson. "It's the biggest sporting event in the world that I'm missing out on. I can't be part of it, and it's upsetting."

The 29-year-old is the captain of her country's track and field team for the Games in August but had earlier said her preparations had been hampered by a "niggly hamstring".

She only returned to competition on June 5 at the Diamond League meet in Birmingham, a year and a day after breaking her left wrist in a racing accident in Rome. She had three races in Europe before returning to Australia to work on her speed, skipping a scheduled run in Stockholm.

Australia's Olympic team leader Kitty Chiller said Pearson's absence was "devastating for us and the team".

"It was always an uphill battle for Sally to get back to her best form in Rio," Chiller told a news conference before Pearson confirmed her withdrawal.

"If anyone was going to do that, she would have done it because she's such a huge fighter."

Pearson had strapping on her left hamstring when she raced in Birmingham, and trailed home in seventh place in 13.25s, almost a second slower than her personal best and a time she described as "disgusting".

In a blog post on June 18, Pearson reflected on the "broken bones, torn calf, degenerative achilles and hammy problems" that have plagued her over the past year.

"What brings athletes back even after we get pushed down time and time again from disappointment?" she wrote. "For me, it's the excitement, the fun and the pure determination that I can overcome the setbacks and still deliver my best."

But at the time, Pearson also admitted she was struggling for fitness.

"I have now been home for six days. I have left nothing in the tank on my return," she said. "Training has been intensely hard and I am exhausted from it but at this stage, I have absolutely no other choice if I am going to be competitive in Rio.

"I have just less than nine weeks until I compete and I am going to do everything in my power to be the best athlete I can be while representing my country in the biggest sporting event in the world."