Coach Andrew McDonald acknowledged Australia underachieved in South Africa but called for calm and backed his team in the face of the flood of criticism that has come their way after the 2-1 series loss to the Proteas.

The timidity with which Australia conceded defeat on the final day of the third Test at Newlands last weekend - bowled out for 111 in pursuit of 288 - sparked calls for heads to roll in the team, team management and board of selectors.

"It's still a very good cricket team with a lot of very good players in there," McDonald told reporters in South Africa before the squad headed home.

"Some legends of the game, or down the path they will be acknowledged as legends of the game. So we've got to balance that out with who comes in, what the next decisions are."

Critics have accused Australia of sticking with underperforming players and not managing the transition of an ageing Test squad.

The Newlands defeat was their third in five Tests, costing them the number one world ranking and jeopardising their campaign to reach a third straight World Test Championship final next year.

They next have a four-Test home series against New Zealand in December and January followed by a trip to India to play a five-match series.

McDonald conceded that Marnus Labuschagne had probably blown his chance to continue with 131 runs at an average of 21.83 in the series, but did not entirely close the door on the 32-year-old top-order batsman.

"We believed in Marnus for this tour, we'll have to reassess that as we move forward," McDonald said.

"There's still a very good cricketer there. Every time he drops back to state level, he outperforms the others ... But he hasn't taken his opportunity on this tour."

Steve Smith scored 83 runs in the first two Tests in South Africa but withdrew from the decisive third with a neck problem. McDonald said he did not think the experience had moved the 37-year-old any closer to making a call on his retirement.

"We are planning for him to play against New Zealand in Perth," McDonald said.

"I think first and foremost, it's understanding what's going on with the neck issue ..."

McDonald pointed to the successful return from injury of Cameron Green and a century from Smith's replacement Josh Inglis in the third Test as batting positives from the tour.

Nathan Lyon, 38, probably suffered by comparison with South Africa's off-spinner Simon Harmer, who took 14 wickets over the series and played a decisive role in the Newlands Test.

"I don't think it's something to review now," McDonald said of Lyon, who took six wickets in the two Tests he played.

"I think we sit back and we'll go through (Sheffield) Shield cricket. Nathan will be preparing for the first Test match in Perth."

McDonald said competing in foreign conditions was always a challenge but acknowledged Australia had not played as well as they might have in South Africa.

"In the emotion of the current situation ... my answer ... would be we've underachieved here," he said.

"I think people put a lot of sort of premium on the key series, and that's ultimately where you are judged. We understand that, we realise that."