Selector Tony Dodemaide says picking Ashton Agar and Matt Renshaw has ensured Australia have been able to "cover all bases" for the final Test against South Africa.

Australia are on the brink of qualifying for the World Test Championship final after securing a first Test series win at home to the Proteas for 17 years.

They took an unassailable 2-0 lead in emphatic fashion at the MCG, hammering the tourists by an innings and 182 runs.

Cameron Green and Mitchell Starc are out of the third Test at the SCG after suffering broken fingers in Melbourne, so the selectors have bolstered the squad by calling up spinner Agar and batter Renshaw.

Agar has not played for his country in the longest format since September 2017, while Renshaw last played a Test against South Africa in March 2018.

Josh Hazlewood returns after recovering from a side strain, while paceman could make his debut in a Test that gets under way next Wednesday.

Dodemaide revealed Australia are keeping their options open and will make a call on the team after looking at the pitch in Sydney.

"It's a blessing to have Josh returning while Lance offers a genuine point of difference with his raw pace and skill," Dodemaide said.

"This squad will cover all bases for when we get to Sydney and assess the conditions closer to the Test match."

He added: "Matthew [Renshaw] is included as a versatile batting option who is in good form, including an unbeaten century in the recent PM's XI tour match against the West Indies

"Ashton offers a second spin option should the Sydney pitch be conducive to turn, as it has done in the past. He also brings a solid batting component."

Australia squad: Pat Cummins (captain), Ashton Agar, Scott Boland, Alex Carey, Marcus Harris, Josh Hazlewood, Travis Head, Usman Khawaja, Marnus Labuschagne, Lance Morris, Nathan Lyon, Matt Renshaw, Steve Smith, David Warner