Australia's under-pressure top order loom as vital in determining the Gabba Test, with data showing the first two wickets of each innings most crucial in Brisbane.

Saturday's third Test start looms as vital in the outcome of the Border-Gavaskar Trophy, with the series locked at 1-1.

Australia's fate could rest in the hands of Nathan McSweeney, Usman Khawaja, Marnus Labuschagne and Steve Smith, all of whom have faced scrutiny this summer.

Data shows that in the last 10 Tests in Brisbane the side that has scored the most runs out of their opening two wickets of both innings has won nine of them.

The only exception is the low-scoring 2022 Test, where South Africa managed a combined 30 from their first two wickets across both innings to Australia's 26.

Otherwise, the start of each innings has proven decisive.

Australia carry some advantage into the Gabba, with their top three of McSweeney, Khawaja and Labuschagne all Queenslanders at some point in their career.

"It's definitely a new-ball wicket and if you can get past that it's a lovely ground to bat at," McSweeney said.

"Batting well at the Gabba is leaving well. It has great bounce, and you can trust that bounce here.

"It's about not fighting that bounce and scoring square of the wicket.

"And being able to spend long time out there. It's a ground where if you spend long times out there the game can open up and you can score quite quickly."

India's top order has also had its problems to start the series, only passing 70 for the second wicket in their match-defining second dig in Perth.

Australia have had similar struggles against Jasprit Bumrah, with McSweeney, Khawaja and Smith all yet to post half-centuries.

McSweeney has however shown signs of promise, with his fighting 39 on the opening night in Adelaide crucial.

After scores of 10 and 0 on debut in Perth, McSweeney said his confidence had not been dented.

"When you don't make runs you're always disappointed and you trying desperately to get a score to cement your spot in the team," McSweeney said.

"But the view from that game from the people I have in my corner, I got two good balls in Perth on a wicket that was tiring as well.

"I got some confidence to go to Adelaide and be clear and really trust my game.

"It's nice to get a little bit of a score now and know I can grow from that. And if there is a bit of pressure, hopefully I can get through that and put on a score in Brisbane."

The opener's runs also helped him win the backing of his predecessor David Warner.

"He's had four of probably the five hardest jobs when it comes to an opening batsman, and I think he's handled it well," Warner said.

"There's a lot of question marks around why they chose him, but the glimpses that you've seen, we now know why.

"He's got a good temperament, I like the way he sets up, and I think he's got a good future ahead of him."