Opener Nic Maddinson has been confirmed as the first omission to Australia’s side for their series-defining Test against South Africa in Cape Town.

On Monday, chief selector George Bailey locked in what may be the first of several changes to the line-up on the back of an embarrassing innings-and-31-run loss to the Proteas in Gqeberha, with Maddinson to return home alongside reserve wicketkeeper Sam Harper.

Despite having not made a Sheffield Shield appearance since March of last year, Maddinson was given a stunning call-up on the eve of the series after all-rounder Cam Green suffered an abdominal injury.

The left-hander managed only 56 runs across his four innings at the top of the order — 48 of which came with his side well on top in the second innings in the series opener in Durban.

He was thoroughly worked over by South Africa superstar Kagiso Rabada in the second Test, making zero and eight.

While defending what was one of the most stunning selection decisions in Australia’s Test history, Bailey said the selectors had not discarded the 34-year-old and he would remain in their thoughts for both the upcoming home series against New Zealand and January’s tour of India.

“Performance wise, would you like more runs? Yes,” Bailey said.

“Did it allow us to set the rest of the team up the way we wanted to, whilst we were working with the group we had? Yes.

“We always talk about what do we see when we see players at their best. I think you saw a glimpse of that in the second innings in Durban.

“With him going home, it was wanting to be clear to him it wasn’t a stopgap . . . (it was) just being clear with he and Harps that they were here for the right reasons.”

Meanwhile, Australia coach Andrew McDonald confirmed star batsman Steve Smith will need to confirm his fitness to feature in Cape Town after battling a neck issue in the second Test.

Smith only batted briefly at Australia’s main training on Sunday local time, but will attempt to spend more time in the nets at another session today.

“I think he had about 20 odd minutes in the nets, give or take (yesterday). Today, he’ll progress that,” Australia coach Andrew McDonald said.

“He didn’t have his helmet on yesterday as well, so that’ll take place and hopefully progresses.

“You’ll see that play out, in terms of what happens, but we’re confident that he will be available.“

If Smith is unable to feature in the third Test, a reprieve could be offered for under-pressure No.3 Marnus Labuschagne, who is facing more heat on his place after a horror second innings dismissal in Gqeberha.

Having once again made a start, the Queenslander’s attempt to loft Simon Harmer over the infield with his side still requring another 226 runs to make the Proteas bat again was caught by Marco Jansen at long on to send him on his way for 39.

Bailey said the selection panel was still “seeing some good things” from Labuschagne at the crease.

“(He’s) still contributing with his ability to get through a number of balls,” Bailey said.

“It’s a decision around what does it look like he gets through there? And is it helping others around him and helping the team get a result we ultimately want?”

Australia’s selectors will also need to make another big call on the composition of their bowling line-up, with a pitch at the Newlands Cricket Ground bearing less live grass than what they were confronted with at St George’s Park likely to leave off-spinner Nathan Lyon in the frame for a recall.

In Gqeberha, Lyon was dropped in favour of Scott Boland, who backed up a five-wicket haul in his side’s only bowling innings with a determined 40 from 166 balls as the nightwatchman across the final two days.