Coach Andrew McDonald admitted on Monday that Australia "let our standards slip" in a stinging first home test loss to Bangladesh, but defended his ageing team saying they have "a fair bit of cricket left in them".
Bangladesh pulled off a massive upset in Darwin on Sunday when they crushed the world's top-ranked side, who were at full strength, by nine wickets.
Bangladesh had never won a test in Australia before.
"We were poor this test match," McDonald said. "Any time you score (fewer than) 500 runs over two innings on that surface, we've got to make some improvements.
"It's tough to accept. We let our standards slip."
The sides meet for the second test in Mackay on Saturday, with McDonald and the selectors facing some tough decisions as pressure mounts for change.
Opener Jake Weatherald and No 3 Marnus Labuschagne are in the spotlight after repeated failures, with former captain Ricky Ponting among those leading calls for a top-order overhaul.
McDonald said he was open to expanding the 13-man squad, which was named for both tests.
"We usually travel with a few more than that, so I think Bails (chief selector George Bailey) left it very open so we could add depending on what we saw," he said.
"We'll make those decisions in the coming days."
Matt Renshaw would be a potential replacement for Weatherald, although youngsters including Sam Konstas, Campbell Kellaway, Ollie Peake, and Cooper Connolly also have their backers.
Allrounder Cameron Green is the only player in the current squad aged under 30 and some commentators want to see "regeneration" as Australia prepare for up to 20 more tests over the next 12 months.
McDonald suggested there would be no kneejerk reaction.
"It's always going to be a conversation, the age profile of the team, where we're at, how we're travelling. A loss doesn't help that," he said.
"But these players have got a fair bit of cricket left in them, I believe. It's just really how we navigate through it.
"You feel a test loss," he added. "It means a lot to them to play for Australia, so let's not lose that in all this as well."