Training regime

The exit of the main attraction sucked the enthusiasm out of the crowd for the morning's remaining heats and counts as an embarrassment for Swimming Australia, which has been under fire for funding Thorpe's expensive training regime in Switzerland.

Australia's Ian Thorpe looks at his time after swimming during the men's 100m freestyle heats at the 2012 Australian Swimming Championships to qualify for the 2012 London Olympics, in Adelaide March 18, 2012. [Photo/Agencies]

"Right from the outset it wasn't about London, per se," Australia head coach Leigh Nugent told reporters.

"London was part of his plan with what he wanted to achieve, but that part isn't going to come to fruition. But the part of swimming beyond London is just validated is what he intends to do and he indicated that in late October."

Nugent said Thorpe has only returned to elite training in September, leaving him only six months to prepare for the trials.

"He almost got there, but he couldn't quite make it. He needs another six or seven months to then go into another highly intense training that he's used to and that his body responds to.

"So what he attempted was incredibly difficult and coming here and doing what he's done is an achievement in itself, but it's part of a bigger process.

"He's (still) got it, he's such a magnificent swimmer."

Samantha Hamill qualified fastest into the semi-finals of the 200 butterfly ahead of twice-Olympic medley relay champion Jessicah Schipper, while Olympic silver medallist Brenton Rickard set the pace for the semi-finals of the 200 breaststroke.

Triple Olympic champion Stephanie Rice will bid to qualify for the Olympic 200 individual medley in the final in the evening session after already winning the 400 IM title on the opening day of the trials.