Michael Cheika suggested he might be done with the tinkering after trimming his squad to 28. Photo: Craig Golding/EPA

MELBOURNE – Australia coach Michael Cheika's hopes of fielding a settled side during the Rugby Championship have been dented by a midfield injury blow but the Wallabies will head into the tournament with some optimism, if not outright confidence.

With Samu Kerevi and Tevita Kuridrani both ruled out of the tournament, the versatile Reece Hodge is tipped to be thrown the number 13 jersey and faces a baptism of fire in the position against the All Blacks in Saturday's opener in Sydney.

The Wallabies will otherwise bring a strong squad, with breakdown menace David Pocock returning after missing last year's tournament while on a sabbatical.

Winger Dane Haylett-Petty and flanker-captain Michael Hooper have also been cleared from injury, while Matt Toomua has returned from England to reinforce the backline in an outfit keen to test the All Blacks a year out from the World Cup.

Cheika has blooded some 30 players in the test arena since the 2015 global showpiece but suggested he might be done with the tinkering after trimming his squad to 28 earlier in the week.

He will hope to put more miles in the legs of some of the younger players still finding their feet, including Izack Rodda and fellow lock Lukhan Tui, who can also slot into the back row.

Wallabies skipper Michael Hooper has been cleared to play after injury. Photo: David Moir/EPA
Wallabies skipper Michael Hooper has been cleared to play after injury. Photo: David Moir/EPA

The Wallabies have slumped to fifth in the world rankings after losing four of their last five tests, including a hard-fought 2-1 series defeat to Six Nations champions Ireland in June.

Yet the gloom that has hung over Australian rugby since the 2015 World Cup has lifted a little this season, with emerging players bolstering a pack that has often suffered from a lack of depth.

South Africa and Argentina aside, key to a successful Rugby Championship for the Wallabies will be a good first-up showing against the All Blacks after they were eviscerated by Steve Hansen's team in the last two tournament openers.

Cheika has tried to change that pattern by putting his squad through a practice game against a Super Ruby selection for the first time in the hope his players will be more match fit.

The Wallabies can at least bring happy memories of their last clash against the world champions, having snapped a seven-game losing streak to them in Brisbane in October.

The match was not a part of the Rugby Championship, and was also a dead rubber in the annual Bledisloe Cup series contested between the trans-Tasman nations.

But it was still a psychological breakthrough for a team that suffers more from a lack of self-belief than quality.

Stopping the All Blacks machine will require 80 minutes of disciplined, high-intensity rugby, a demand that has proved beyond the Wallabies on a consistent basis.

A failure to do so in Sydney, at least, would almost certainly mean another battle for second place with South Africa and more doubts about the Wallabies' chances of winning a third World Cup next year.