Australia's one-day batsmen are under mounting pressure to keep their places after a lacklustre series defeat to South Africa, captain Aaron Finch warned on Monday, with a potential shake-up looming.

While the host won in Adelaide to snap a seven-game losing streak, it crashed heavily in Perth and lost in Hobart by 40 runs.

None of its key batsmen performed consistently, although number three Shaun Marsh hit a fighting 106 in the decider on Sunday.

Finch admitted, “We're all under pressure when we lose, no doubt about that” and hinted at changes ahead of Australia’s next series against India in January.

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“Between the batting line-up not having got it right for a little while now there's going to be questions asked whether it's Maxi, Lynny, Heady, or myself or Stoin,” he said, referring to Glenn Maxwell, Chris Lynn, Travis Head and Marcus Stoinis.

“It's important that we really nut out the balance of the side and get that right over the next two months.

“We have to either adapt our game plan a little bit around the way the side structures up best or we slightly change our personnel to fit a style that we think can win.”

Big-hitting Lynn was elevated to open the batting in Hobart in a bid to get quick runs on the board, but it failed spectacularly when he was out first ball.

Despite this, Finch said the powerful right-hander, a prolific scorer in Twenty20s, is likely to open again as Australia look for more aggression early in the innings.

“Yeah, it could be a long-term plan,” he said.

“It was an attacking option to put Chris at the top, to change him and Travis (Head), to put a couple of guys up there who can get us off to a flyer. It was an attacking move,” he added.