Australian test captain Pat Cummins conceded another pace option could have "potentially" made a difference in taking the remaining wickets for a 3-nil series victory over South Africa at the SCG while Gulidjan star Scott Boland sat on the sidelines.

Coming into Sunday the home side required 14 wickets for a clean sweep, falling eight shy as the steadfast Proteas looked largely untroubled batting out the day.

A rain-soaked end to the summer in Sydney kept the likelihood of a spin-friendly pitch from properly developing.

It meant Nathan Lyon took the bulk of overs and Australia left relying on part-time options with Cummins and the incoming Josh Hazlewood the only seamers picked for the final test.

Pace repeatedly looked the biggest threat to South Africa as the match laboured toward a drawn result.

"We thought it was going to spin a bit more than it did," Cummins said in a press-conference following play.

"There was maybe, I haven't done the maths, only 250 overs on that wicket. Maybe it (a third pace option) might have made a bit of a difference."

Much of the scrutiny has been directed at controversial decisions from the third umpire on a number of caught dismissals being overturned.

After Australian pace duo Cameron Green and Mitchell Starc were ruled out of the fifth test with Injury, Boland also made way for former test opener Matt Renshaw and allrounder Ashton Agar to join Hazlewood in making up the 11.

Cummins maintained Agar's inclusion was not a "audition" as a second spinner ahead of a tour to spin-dominated subcontinental conditions in India starting next month.

Despite the faith shown to cover the batting and bowling abilities of Green, Agar failed to take a wicket in either of South Africa's innings and dropped a number of catching opportunities, only becoming increasingly crucial as the win fell further out of Australia's grasp.

The skipper defended the selection decision and efforts of Australia's bowling brigade in the frustrating contest.

Boland's omission came after three tests, taking 10 wickets across six innings at an average of 16.42 across the summer.

The seamer, only the second Indigenous player known to have represented Australia in official tests, now has 28 test wickets at an incredible 12.21 each.

Australia wrapped up their 2022-23 home tests four wins from five, ending their final match in a draw declaring 4-475 and seeing South Africa score 255 and finish 2-106.