It's been a summer to forget for the tourists, conceding cricket's little urn in a 4-0 Ashes thumping, but the ODI battle is expected to be a far closer battle. Australia have slipped to No.3 in the International Cricket Council's rankings, while England is fourth but building momentum before next year's World Cup on home soil.

The tourists have Eoin Morgan as skipper, allowing Joe Root to concentrate on his batting, and have power hitting at the top of their innings.

Morgan said his squad, although it did feature several players from the Test series, had a refreshed mentality.

"A lot of the guys that come into the squad, who haven't been here a great deal, have come from various places around the world, bring a lot of energy with the group," he said.

"I think over the last couple of years we have managed to distinguish between those two formats. We are trying to do two different things, as a Test team and a white-ball group.

"We are here to win and we do that by playing the way we play - that's, in essence, the most important part of our game, taking our game to the opposition and adapting."

The Australians are also keen to adapt, having won only five of 15 completed one-day internationals last year.

Smith suggested on Saturday it was time for a sharpened focus, with the World Cup defence not far off.

"It's a good opportunity for us to try and change our one-day cricket a bit. We have probably been hot and cold in the last 18 months and we want to set that right - a good opportunity starting here (on Sunday)," he said.

The world champions have struggled to get going in the middle order over the past year, and have turned to South Australian skipper Travis Head to be the key man at No.4.

Head had a modest tour of India on the eve of the home summer and has averaged 37.36 in 30 one-day internationals, with his lone century coming before his home crowd against Pakistan last summer.

"I think he is a player with a really bright future. He is captain of his state, he has a good cricket brain, and we just need someone that has got some smarts there in the middle and play the right brand of cricket at the right time," Smith said.

"Whilst he didn't have his best time in India, he has played some really good cricket here at home. He looks like he is hitting the ball quite well. Hopefully, he can have a big impact for us in this series."

Aaron Finch and David Warner will open the batting - should Warner recover from gastro in time. The Australian vice-captain walked laps of the MCG on Saturday but did not bat. He missed training on Friday.

"I think he is OK. He was having a bit of a gastro issue yesterday (Friday). He turned up here today. I think he walked the oval here a few times and he said he would be fine. I don't think there will be any trouble there," Smith said.

Smith did not reveal who would fill the No.5 and No.6 slots, with three men appearing to jostle for those spots - the recalled Cameron White and all-rounders Marcus Stoinis and Mitch Marsh.

Stoinis is averaging 86.25 with a strike rate of 100 in eight matches and had been in excellent touch in the losing ODI series in India.

White replaced Glenn Maxwell in the squad, whose form issues ultimately led to his demise. It's understood the national selectors have made it clear to Maxwell what he needs to do to return.

Smith said White, who was shocked to earn a recall aged 34, deserved his chance and offered more than just his batting.

"He has got some experience. He is also a very good fielder - he has got some terrific hands and does have smarts about him. He fills a lot of gaps and is someone you like in your team. It just comes on the back of his form over the last three years. He has put the numbers up again and again and deserves an opportunity," he said.

Smith and Maxwell addressed any issues the pair may have had on Friday, with the captain unwilling to divulge what was said other than to say: "I get on really well with Glenn. It was good to catch up and just have a chat."

Paceman Josh Hazlewood has remained at home in Sydney and will be rested in Melbourne. Fellow quick Pat Cummins is likely to be rested from Friday's clash in Brisbane.

Squads: Australia: Steve Smith (c), David Warner (vc), Pat Cummins, Aaron Finch, Travis Head, Mitchell Marsh, Tim Paine, Jhye Richardson, Mitchell Starc, Marcus Stoinis, Andrew Tye, Cameron White, Adam Zampa, Josh Hazlewood (rested in Melbourne)

England: Eoin Morgan (c), Moeen Ali, Jonny Bairstow, Jake Ball, Sam Billings, Jos Buttler, Tom Curran, Alex Hales, Dawid Malan, Liam Plunkett, Adil Rashid, Joe Root, Jason Roy, David Willey, Chris Woakes, Mark Wood.