Cathy Freeman is worried that Jana Pittman could exacerbate her knee injury if she runs at the Athens Olympics.

Pittman faces a race against time to be fit for the heats of the 400m hurdles on August 21 after damaging the lateral meniscus in her right knee last weekend.

Freeman knows all about the pressure of being Australia's stand-out athletics gold medal hope, having carried the hopes of a nation en route to victory in the 400m in Sydney four years ago.

"I just hope she makes the right decision," Freeman said.

"I'm a little bit frightened for her because you have to think about the future."

Freeman was speaking during a break in filming for a commercial on behalf of People for the Ethical Treatment of Animals (PETA) and their campaign to end live sheep exports.

"I'm worried because I can imagine it from (Pittman's) point of view - if she goes in the race she could do further damage to the injury she has at the moment," said Freeman.

"But at the same time if she feels it in her heart to get out there and race then she has to follow her heart.

"What I would suggest is to follow her heart and try and be smart and make a brave decision."

Freeman's last major international race was alongside Pittman when they won gold in the 4x400m relay at the 2002 Commonwealth Games.

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