If David Warner's performances post his last two children's arrivals are anything to go by, South Africa should be on high alert.

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Warner returned to Australia's World Cup camp on Wednesday evening ready to begin his preparations for the Proteas on Saturday.

The left-hander was the only player missing from Wednesday's optional training session at Old Trafford, as he travelled from London to Manchester after the birth of his third daughter.

However, he'll return to train with the team on Thursday, avoiding missing any games as Australia enter the business end of their title defence.

And if his dominating form at the World Cup wasn't sign enough he'll be ready to go, Warner's history is.

Warner, wife Candice and daughters Ivy and Indi celebrate Australia's 2017/18 Ashes win // Getty

After the birth of his first child, Ivy Mae, in 2014 he hit strung together a number of impressive knocks - culminating in a century in his first Test match that followed.

Two years later when Indi Rae was born, he hit scores of 93 and 122 for Australia in the next two one-dayers he played.

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"Hopefully some more success can follow after his third," teammate Glenn Maxwell said.

Warner's ability to switch on when he returns to field is no doubt helped by the fact he's accustomed to light build-ins to matches.

He is a noted non-trainer the day before games, dissimilar to the likes of Steve Smith and Aaron Finch who spend hours in the nets.

"He's still a hard trainer," Maxwell said.

"You've seen him go through a few different training methods - he's had the headphones in listening to music.

David Warner on the music he's been playing in his earphones at training... and why #CWC19 pic.twitter.com/CM2e61kIMA — cricket.com.au (@cricketcomau) June 27, 2019

'He was batting in sunnies the other day at Lord's. He's always trying something new.

"He's been unbelievable for us, his success up the top with Finchy has been a key to getting us where we are in this tournament."

Warner remains the third highest scorer in the tournament, with 516 runs at 73.71. Finch is just 12 behind him, in fourth.

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Australia will finish first with a win over South Africa on Saturday.

That will set up a likely semi-final clash with New Zealand in Manchester on Tuesday, unless Pakistan obliterate Bangladesh by enough to rise to fourth.

A loss, however, could mean a far more difficult path for Australia, assuming India beat Sri Lanka.

They would travel to Birmingham for a semi-final against England at Edgbaston on Thursday, and have just a three-day turnaround into the final if they prevail.

"The incentive to finish top would be great," Maxwell said.

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"To get as much time as you can in one place, you don't have to pack your bags again.

"To have that at this end of the tournament would be nice."

2019 World Cup

Australia's squad: Aaron Finch (c), Jason Behrendorff, Alex Carey (wk), Nathan Coulter-Nile, Pat Cummins, Usman Khawaja, Nathan Lyon, Shaun Marsh, Glenn Maxwell, Kane Richardson, Steve Smith, Mitchell Starc, Marcus Stoinis, David Warner, Adam Zampa

June 1: Australia beat Afghanistan by seven wickets

June 6: Australia beat West Indies by 15 runs

June 9: Australia lost to India by 36 runs

June 12: Australia beat Pakistan by 41 runs

June 15: Australia beat Sri Lanka by 87 runs

June 20: Australia beat Bangladesh by 48 runs

June 25: Australia beat England by 64 runs

June 29: Australia beat New Zealand by 86 runs

July 6: Australia v South Africa, Old Trafford (D/N)

July 9: Semi-Final 1, Old Trafford

July 11: Semi-Final 2, Edgbaston

July 14: Final, Lord's

Sync Australia's World Cup schedule to your calendar HERE

For a full list of all World Cup fixtures, click HERE