Steve Smith will open the batting alongside Usman Khawaja against the West Indies in place of the retired David Warner, Australia selectors said Wednesday, with allrounder Cameron Green coming in at No 4.
Warner bowed out of test cricket the weekend after the last test against Pakistan in Sydney, having been a fixture at the top of the order for 12 years.
Recognised openers Cameron Bancroft, Marcus Harris and Matt Renshaw were long seen as the main contenders to fill the role, until Smith last week said he wanted to do the job.
"Steve Smith will be opening the batting and Cameron Green will be coming into the No 4 position which is fantastic," chief selector George Bailey told reporters.
"Steve's motivated and energised and keen to do it.
"It's a challenge for him, it's something ... he thinks he can do. It's an itch he'd like to scratch and ultimately for us, as a team, it's something that fits."
The highly-rated Green has been sidelined recently by a resurgent Mitchell Marsh, who has assumed the allrounder role.
Shifting Smith up the order, rather than opting for a specialist opener, allowed selectors to bring Green back primarily as a batsman.
"The way the rest of that batting order is functioning left us feeling like we have someone who we think is pretty talented, who potentially was going to find it hard to get any test cricket in the next period," Bailey said of Green.
"I don't think that's going to be particularly beneficial for Greeny. We can get a lot of benefits out of him playing."
Renshaw was handed a test lifeline as the only change in a 13-man squad for the two-test series starting on January 17 in Adelaide, leaving Bancroft and Harris out in the cold.
His inclusion is a big blow for Bancroft, who is the leading run-scorer in Sheffield Shield over the last two seasons. But at 27, Renshaw is four years younger.
Whether pace spearheads Pat Cummins, Josh Hazlewood and Mitchell Starc, who played all three tests against Pakistan, can back up for another two is another unknown.
If selectors decide to rest one of them, Boland will step in.
Selectors also named a 13-man squad for the one-day series against the West Indies that follows the tests, with Cummins rested and Smith taking over as captain.
Marsh, Starc, and Hazlewood will also sit out the three games
Australia test squad: Pat Cummins (capt), Scott Boland, Alex Carey, Cameron Green, Josh Hazlewood, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Mitchel Marsh, Matt Renshaw, Steve Smith, Mitchell Starc
Australia ODI squad: Steve Smith (capt), Sean Abbott, Nathan Ellis, Cameron Green, Aaron Hardie, Travis Head, Josh Inglis, Marnus Labuschagne, Glenn Maxwell, Lance Morris, Jhye Richardson, Matt Short, Adam Zampa