Quade Cooper, the Australian fly-half, missed training because of illness yesterday in a blow to the Australians on the eve of the Tri Nations opener against South Africa.
Cooper has been restored to the team after being rested for last week's upset loss to Samoa and was expected to play a part in Australia's attempts to get back to winning ways at the Olympic Stadium today.
A spokesman for the team said that Cooper, 23, was suffering from a stomach illness, but the captain Rocky Elsom said that the New Zealand-born back should be fit to face the Springboks.
"If he's not feeling that well, it's probably a good move not to train, but I think he'll be fine," the flanker said.
Kurtley Beale, the full-back, stepped into the fly-half position in training and would be the favourite to take the No 10 shirt if Cooper does not recover in time.
That could also mean a surprise recall to the squad for the experienced Matt Giteau, who had a poor game in the 32-23 loss against Samoa and was left out of the team to face South Africa.
Another concern for the Wallabies has been the torrential rain falling on Sydney, which could reduce the game to a tight, forwards-dominated contest and rob the home side of the advantage their backs would be expected to bring to the clash.
Elsom, however, said he was not expecting Sydney's wettest July in 50 years to be that much of a factor.
"We've got a game plan, we think, that can adapt to both," he said. "Obviously if it's as it is now, it's not going to be as free-flowing, but that's not necessarily a problem.
"Even then, you're talking about perceived strengths, and what happens when you get out there can be different."
After the Samoa defeat, a season that started with talk of a first Tri Nations title since 2001 and a third World Cup title has this week become a quest for respectability.
"I think after the outing we had, our emphasis has been on us," Elsom said.
"When you have a performance that didn't go the way you wanted, you want to get out and play the next day.
"It's only been six days, so we're pretty keen to get out there."