Darren Lehmann has forecast changes following Australia's capitulation in Hobart, where they were skittled for just 85 early on day one of the second Test against South Africa.
Lehmann and chairman of selectors Rod Marsh settled on three changes for the match, calling up Joe Burns, Callum Ferguson and Joe Mennie in place of Shaun Marsh (broken finger), Mitch Marsh (dropped) and Peter Siddle (back).
Australia have made at least one change to their XI for every match in a current four-Test losing streak, which started in Sri Lanka earlier this year.
Some of those have been forced by injuries or conditions but as it stands now, Australia's first-choice side is far from settled.
"We believe this is the best squad we've got to play. On today's performance you'd say we've got to change," Lehmann said.
"We've got to find a way to get through those tough periods and we haven't done that in the last 4.5 Test matches now."
There is nobody dominating Sheffield Shield to a point where they will demand selection for the third Test, a day-night clash at Adelaide Oval.
Burns and Ferguson will almost certainly be given more time to prove themselves, while Usman Khawaja is likely to be as much an automatic selection as David Warner and Steve Smith given his fine second-innings knock in Perth.
That leaves Adam Voges, who hasn't passed 50 during Australia's four-Test losing streak and was out for a golden duck in Hobart.
If Voges fails to produce an innings of substance at Bellerive he could be dumped, despite averaging 64.47 with the bat.
Lehmann wouldn't be drawn on when Mitch Marsh might return to the XI, having been dropped for the first time since the fourth Test of the 2015 Ashes.
"Mitch will go back to Shield cricket. I'm sure he'll play well and be back at some stage," Lehmann said.
"The challenge for him is to make a lot of runs and keep getting wickets."
Lehmann rejected concerns raised by former Test players Mitchell Johnson and Chris Rogers about selectors' communication with players.
National selector Mark Waugh suggested last week that Marsh "definitely has two Tests" to prove he belongs at Test level.
"I don't think it's mixed messages, the players are fine. Rodney talks to them before the match all the time, they know what's going on - very clear," Lehmann said.
"Whether they agree with it or not is a different scenario."
