George Bailey believes Australia's top order should take their share of responsibility for the team's poor performances in South Africa so far.

The tourists suffered a six-wicket defeat as Quinton de Kock ran riot in the opening one-day international in Centurion, before Faf du Plessis' century inspired a 142-run win for the hosts in Johannesburg.

Australia's young bowlers have borne the brunt of the criticism for their expensive figures in the wake of those defeats, but Bailey insists the team's batsmen also have a case to answer.

"We've certainly got a young bowling attack, but I think the thing that's been the most disappointing is our batting the last two games," he is quoted as saying by ESPN Cricinfo.

"We were under par in game one and 360 is a big total, but you saw it on that ground it was great value for money, the ball flew everywhere and our run rate was going pretty well.

"All the batters are hitting the ball pretty well, it's just that nobody's getting a hundred and the South Africans have had a guy score a hundred in each of those games.

"As much as the focus could be on our young bowling attack, I think it's the batters who have got to step up."

Victory for South Africa in Durban on Wednesday will wrap up victory in the five-match series for the Proteas.