Australia are set to use their five-match ODI series against South Africa to settle on their preferred opening partnership for the World Cup, with Travis Head, Mitch Marsh and David Warner locked in a three-way battle.
Head plundered 91 off 48 balls on Sunday as Australia wrapped up a 3-0 T20 series whitewash against South Africa in Durban.
Mitch Marsh was named player of the series after producing knocks of 92no, 79no and 15 in a dream start to his captaincy tenure.
With Pat Cummins (fractured wrist) still sidelined, Marsh will also captain the side in the ODI series against South Africa, starting in Bloemfontein on Thursday.
Warner has been a lock at the top of the order for most of his glittering 142-match ODI career, but Marsh and Head's hot form pushed him to No.4 when Australia faced India in March.
Australia have just eight matches to prepare for the October 5-November 19 ODI World Cup in India - the five against South Africa, and a three-match series in India.
Assistant coach Michael Di Venuto said the series against South Africa was a chance for players to press their case to open at the World Cup.
"There's lots of options for us moving forward opening the batting," Di Venuto said.
"If you look at the World Cup, David Warner comes back into the mix, Mitch Marsh, Travis Head.
"They've all got good form recently that they can all put a case forward to open the batting at the World Cup."
Star batsman Steve Smith (wrist) and paceman Mitchell Starc (groin) will miss the ODI series against South Africa.
Smith's injury meant Marnus Labuschagne earned a late call-up for the South Africa ODI tour, and he's keen to push his case to bat at No.4 for the World Cup.
Spinner Adam Zampa was left out of the third T20 against South Africa due to a neck injury but is expected to be fit for the ODI series.
"He's fine," Di Venuto said.
"He was sick for the first game, came back for the second - he did his neck in the warm-up.
"It affected him during the second game. There was no point risking a world-class performer like that in game three here.
"It also gave us an opportunity to give Tanveer (Sangha) another game of international cricket."
Di Venuto praised the captaincy of Marsh during the T20 series, describing him as a natural leader.