Winger Drew Mitchell has been placed on standby for James O'Connor who is under a fitness cloud ahead of Australia's Test against Italy in Melbourne on Saturday.

O'Connor announced himself with three tires on his debut against the Italians in Canberra last Saturday but the 18-year-old did not train with the Wallabies at Xavier College on Thursday morning because of stomach cramps.

If O'Connor fails to recover, it is likely that Adam Ashley-Cooper will be elevated to fill the full-back's role, creating a vacancy for Mitchell on the bench.

The Italians have made 11 changes to the line-up which went down 31-8 to the Wallabies in Canberra, but they have retained former Australian rugby league star Craig Gower at flyhalf.

Italian coach Nick Mallett is understood to be agitating for the roof at Etihad Stadium to be left open during Saturday night's clash to create conditions 'as near to normal' as possible.

But Wallabies front-rower Ben Alexander, named to fill an unaccustomed role at tight-head, said his strong preference would be for the roof to remain closed.

"I like playing an expansive game ... and obviously with a closed roof and nice deck it's going to be conducive to that," said Alexander.

"It's something new for me and just guarantees good playing conditions.

"I've never been to Etihad so it's going to be a great experience, I love going to new stadiums and seeing how they compare to all the others.

"I'm looking forward to getting a big crowd and ripping into 'em."