Is this the bravest team of Michael Cheika’s career?

Have Eddie Jones’ mind games had an effect or has Michael Cheika just picked the bravest team of his career?

Have Eddie Jones’ endless mind games finally had an effect or has Wallabies coach Michael Cheika just picked the bravest team of his career to tackle England in the second Test in Melbourne on Saturday night?

Whatever happened, Cheika always had to make two changes this weekend, following injuries to No 8 David Pocock and lock Rob Simmons when Australia was beaten 39-28 to England in Brisbane last weekend.

But he has made four changes, dropping both his props, Greg Holmes and Scott Sio, to change the dynamic up front with tighthead Sekope Kepu and loosehead James Slipper and replacing Simmons with Brumbies lock Sam Carter. But his biggest shock was installing Sean McMahon at No 8, a position he has never played in professional rugby.

“It’s very congested, the race for that No 8 spot,” said Cheika, who bypassed Ben McCalman and Wycliff Palu to reward McMahon’s ultra-physicality.

“I just like what he (McMahon) offers. I also think he deserves that opportunity. He’s been one of the standout players in Super Rugby this year and he’s passionate about how we’re going to play the game.

“He’ll be very clear on the job he needs to do and he’ll go about it very well. I believe in him a lot and what he brings and so do all the other players.”

Asked about the massive weight difference between McMahon and English No 8 Billy Vunipola, who at 126kg is fully 26kg heavier, Cheika admitted he had not even thought that would be an issue.

“He plays the game very physically, so I don’t feel he’ll be dwarfed. I know the English No 8 is a big fellow but that’s how it rolls sometimes.”

McMahon’s heart won’t give out. He will run into the menace of the English forwards all day, not a quiver in his step, but the rules of physics don’t just give way in the face of bravery.

Vunipola, James Haskell and Maro Itoje and all the rest of that hard-shouldered pack will be waiting for him, and the Wallabies better be prepared to fight fire with fire.

Cheika expects England to persevere with their “niggling tactics” but says his side won't retaliate. “That’s not our go.”

The conservative selection, indeed the expected selection, was that Ben McCalman would come in at No 8, allowing McMahon to play his usual destructive role off the bench. But Cheika insists he was picking a team with some substance for the long haul, not just to win on Saturday, and clearly McMahon has staked a claim to be part of that side.

Cheika admitted that while the perception that loosehead Sio was having problems had to be addressed, he made his changes because of the performances of the squad’s two other looseheads, Slipper and Toby Smith of the Rebels.

“Slipper’s an experienced campaigner,” said Cheika. “He’s been around for a fair while even though he’s still fairly youthful. He’s got a lot of Tests. Since he came back into Super Rugby (from injury) he’s been improving every week and he’s been throwing himself around at training and he deserves an opportunity.

“The other thing that’s relevant is the performance of Toby Smith. He’s been outstanding for the Rebels. His ball carrying has been strong, his aggression has been good, his scrummaging has been strong. I want to give him the chance to play.

“Scotty had his chance last week and didn’t take it. Now it’s an opportunity for Toby.”

The scrummaging battle was already shaping up as a critical element but now, on a surface that has shifted under scrums at every Super Rugby match played at AAMI Park this season, it has become life-and-death for the Wallabies.

Carter said the Wallabies had trained last night on AAMI Park for the first time and found the surface was solid, but the real test will come when two 900kg packs go head-to-head.

Having made so many changes in the pack, Cheika left the backline completely unchanged. Samu Kerevi, who debuted in Brisbane, has been retained at inside centre ahead of Christian Lealiifano.

Defeat on Saturday would mean that, for the first time , Australia had lost a series to England at home. Almost as bad, the world No 2 ranking secured by finishing as runners-up to the All Blacks at last year’s World Cup, would be forfeited.