Australia have confirmed three changes for the third and final Test against South Africa at the Sydney Cricket Ground.

The teams for the clash were locked in at the toss, which was won by Australia, who elected to bat first.

South African skipper Dean Elgar said he also would have batted if he won the toss, while also confirming his side have gone with an extra spinner.

The three changes will see the injured Mitchell Starc and Cameron Green miss the side, while Scott Boland has also been dropped after playing Australia's previous three Tests.

That is a straight swap back for the man he replaced in Josh Hazlewood, who returns from injury, while Ashton Agar and Matt Renshaw have also come into the side.

It means Australia will go into the Test with just two specialist quicks, joined by two spinners on a pitch which is expected to be an old-style Sydney Cricket Ground wicket that will take spin.

Lance Morris and Marcus Harris join Boland as the three players to miss out for the Aussies from the 14-man squad.

Marnus Labuschagne was seen in the pre game marking out his run up to bowl medium pace, while Travis Head and Steve Smith can also send down part-time spin.

"It looks like a traditional SCG wicket. It might turn a bit, so best conditions to bat on Day 1," Cummins said at the toss.

"We thought about playing an extra seemed, but it came down to whether we are confident taking 20 wickets with the four guys, and in this case we are."

For South Africa, Heinrich Klaasen has replaced Tehunis de Bruyn who has returned to South Africa, while Simon Harmer plays as the second spinner, replacing Lungi Ngidi.

Harmer and Keshav Maharaj are joined in the five-man attack by Marco Jansen, Kagiso Rabada and Anrich Nortje.

Teams

Australia
1. David Warner
2. Usman Khawaja
3. Marnus Labuschagne
4. Steve Smith
5. Travis Head
6. Matt Renshaw
7. Alex Carey (wk)
8. Ashton Agar
9. Pat Cummins (c)
10. Nathan Lyon
11. Josh Hazlewood

South Africa
1. Dean Elgar (c)
2. Sarel Erwee
3. Heinrich Klaasen
4. Temba Bavuma
5. Khaya Zondo
6. Kyle Verreynne (wk)
7. Marco Jansen
8. Keshav Maharaj
9. Kagiso Rabada
10. Simon Harmer
11. Lungi Ngidi