Australia's XI for the fifth Ashes Test, a pink-ball clash beginning in Hobart on Friday, will remain clouded until medicos cast their eye over bowlers and allrounder Cameron Green.

Selectors' toughest challenge has been created by Khawaja's 238 runs at the SCG, enough to earn man-of-the-match honours in his first Test since 2019.

Pat Cummins admitted it would be "pretty hard" to drop the stylish left-hander, adding he was in "total command of his game" and boasted the versatility required to open the batting.

Travis Head was an enforced omission for the fourth Test after contracting COVID-19, yet started the series with an imposing knock of 152 and is expected to return.

Marcus Harris is the leading candidate to be squeezed out of the side, although selector Tony Dodemaide was quick to highlight how the under-pressure opener's 76 represented the "most consequential innings" of a low-scoring Boxing Day Test.

Dodemaide also flagged that selectors agreed with Cummins about Khawaja's opening credentials, noting "we're confident he could do that".

And the former fast bowler denied it was a simple decision for his panel, also featuring Justin Langer and George Bailey, to pick between Khawaja and Harris.

"That was just a phenomenal performance from Uzzy," he said.

"Having said that, there are a lot of conversations to be had over the next couple of days. It's a very difficult one.

"You need to consider all the options and that's probably the benefit of having three sets of eyes and three minds.

"There's any number of left-field suggestions you come up with and what George has said, and I agree with as well, is 'let's not just think of the obvious'.

"Have the what-if scenarios ... however left field or peripheral that might be, let's just toss it around and see if there's any merit."

Scott Boland's masterful spells at the MCG and SCG are the most obvious example of the panel's bold intent.

David Warner, Steve Smith and Marnus Labuschagne are automatic selections.

Asking Green to sit out the series finale would be a shock move, particularly after his confidence-boosting dig of 74 alongside Khawaja.

But it could become a different proposition if medicos were to raise red flags about the 22-year-old's capacity to get through five Tests of bowling, especially given his age and history of back injuries.

"We'll see how he pulls up," Dodemaide said.

"It was a terrific innings ... and his bowling is really exciting.

"We do have to be mindful that he's still a very young man ... you're always conscious of bowlers and their physical development."

Dodemaide was noncommittal about whether Boland, who has sore ribs, and Mitchell Starc, who is a genius with the pink ball but has played all four Tests, would face England.

"Obviously a couple of bowlers will be sore after a fairly long day on day five," he said.

"We'll get a full (medical) report tomorrow."

Fellow pacemen Jhye Richardson and Michael Neser, who both played the day-night Test at Adelaide Oval, are waiting in the wings.

Australian Associated Press