Batting depth a major worry for Langer

Justin Langer admits nobody is banging the door down as he mulls how to fix both Australia's top six and a national batting crisis.

Langer has added Marnus Labuschagne to what is now a 14-man squad for the fourth Domain Test against India.

Labuschagne is a chance to take Mitch Marsh's place in the XI that folded in Melbourne, where the tourists retained the Border-Gavaskar trophy by snatching a 2-1 series lead.

Peter Handscomb may also earn a recall for the SCG series finale, although Langer's description of Aaron Finch as "a really good player" and "great in the team" suggests the under-fire opener will be spared the axe.

However, Finch could yet be demoted down the order as Langer and Tim Paine discuss the best plan for Australia to avoid suffering their first Test series loss at home to India.

Regardless of how much Langer tinkers before the fourth Test starts on Thursday, it's clear there are big batting problems that extend beyond the squad.

"Try being a selector at the moment," Langer told reporters.

"We've got to be careful not to reward poor performances but ... it's not as if the guys are absolutely banging the door down.

"Most of our batters knocking on the door are averaging in the 30s (in the Sheffield Shield)."

Usman Khawaja's century in Dubai remains the only Test hundred scored by any Australian in almost a year, a horror slump that highlights how much the team relied on banned superstars Steve Smith and David Warner.

The top six's collapses of 3-29 and 3-13 in Australia's first innings at the MCG effectively ended their hopes of defeating India in the series.

Langer acknowledged recent results suggest domestic players are not being adequately prepared to make the step up.

"The art of batting, we've got some work to do," Langer said.

"Whether it's the system ... whether it's something we've got to change in our psyche, I'm not sure.

"It's something everyone is looking at."

The former Test opener, renowned for putting a high price on his wicket, seemingly remains adamant Finch can make the cut in Test cricket after a couple of sloppy dismissals.

Langer noted Finch was having a lean run but also highlighted a pivotal 112-run opening stand in Perth that delivered Australia their first Test win since the Cape Town cheating scandal.

"He's working harder probably than he's ever worked ... he'll be better for this period," Langer said.

"He's the only guy playing all three forms of the game (for Australia) ... he's got to somehow recharge his batteries over and over and over again. It's a great challenge."

Domain Test Series v India

Dec 6-10: India won by 31 runs

Dec 14-18: Australia won by 146 runs

Dec 26-30: India won by 137 runs

Jan 3-7: Fourth Test, SCG

Australia squad: Tim Paine (c, wk), Josh Hazlewood (vc), Mitch Marsh (vc), Pat Cummins, Aaron Finch, Peter Handscomb, Marcus Harris, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Shaun Marsh, Peter Siddle, Mitchell Starc

India squad: Virat Kohli (c), Murali Vijay, KL Rahul, Mayank Agarwal, Cheteshwar Pujara, Ajinkya Rahane, Hardik Pandya, Hanuma Vihari, Rohit Sharma, Rishabh Pant (wk), Parthiv Patel (wk), Ravi Ashwin, Ravi Jadeja, Kuldeep Yadav, Mohammed Shami, Ishant Sharma, Umesh Yadav, Jasprit Bumrah, Bhuvneshwar Kumar