CANBERRA, AUSTRALIA - OCTOBER 24: Cameron Bancroft of the CA XI bats during the tour match between the Cricket Australia XI and New Zealand at Manuka Oval on October 24, 2015 in Canberra, Australia. (Photo by Mark Nolan/Getty Images)

Australia are set to drop a selection bombshell by leaving out widely-tipped young gun Cameron Bancroft for the first Test at the Gabba.

It means the mystery over who will partner David Warner at the top of the Australian order appears to be a two-horse race between Queenslander Joe Burns and WA veteran Shaun Marsh.

Bancroft, 22, was seen as the ideal replacement for retired opener Chris Rogers, due to his temperament and ability to occupy the crease.

He had a boom Sheffield Shield season in 2014-15 and was selected on the cancelled Bangladesh tour with high hopes of making his Test debut.

However, it appears selectors have had a change of heart and may have been swayed by either Burns’ record at the Gabba and the fact he scored a hundred against New Zealand last week, or by the experience offered by Marsh.

After the mass retirements that followed the failed Ashes tour, Bancroft was the selectors’ one chance to inject some fresh blood.