Ian Thorpe can shake off his mystery illness and win both the 100m and 200m freestyle at the upcoming Commonwealth Games, according to swimming legend Dawn Fraser.

The Thorpedo's chances of competing in Melbourne have improved, after blood tests showed he was on the mend.

Fraser, who overcame countless setbacks during her heralded career, believed Thorpe's mental strength would guide the five-time Olympic gold medallist through his troubled build-up to the Melbourne Games.

"I can see him winning both events even with this sickness, he's the type of swimmer who can rise to the occasion and I have no doubt about that not," Fraser told AAP.

"I would not want to put any pressure on him but he has just got the ability to be able to do that."

Fraser is no stranger to coping with adversity, having been hospitalised with bronchial asthma for four days in the week leading up to the 1956 Melbourne Olympics.

She went on to win the 100m freestyle in world record time at those Games and then famously recovered from a car crash in the lead up to the 1964 Tokyo Games.

Her mother died in the accident and she seriously injured her neck but Fraser defied the odds by becoming the only Australian to win the same event at three straight Olympics.

She felt swimmers such as Thorpe and distance master Grant Hackett were more than capable of overcoming poor preparations and still collecting gold.

"I have no doubt in the world that Ian is the type of swimmer that can make it back, like Grant Hackett swimming through that bronchial asthma at the (2004) Athens Olympics and winning the (1500m) gold medal," Fraser said.

"They are the type of men that can do that, they know how far they can push their body and how far they have to push their body and are both capable of doing that."

Thorpe, 23, has shown immense mental resilience on his way to becoming Australia's most successful Olympian and currently holds the world record in the 200m and 400m freestyle.

He is the hottest of favourites for the 200m but faces the daunting challenge of South African duo Roland Schoeman and Ryk Neethling over two laps.

"He may not be 100 per cent fit when he competes, but he will give a 100 per cent shot," Fraser said of Thorpe.

Thorpe has been given permission to spend more time recovering in his hometown of Sydney and doesn't have to fly Sunday for the start of the national swim team's pre-Games camp in Melbourne.

Brought to you by AAP © 2024 AAP