Travis Head will miss at least the first half of the World Cup and possibly the entire tournament as Australia deal with a disastrous finish to their tour of South Africa.
Scans confirmed Head won't require surgery after he fractured his left hand in the fourth one-day international of the five-match series, which Australia ended up losing 3-2 after leading 2-0.
But the selectors will need to decide if it's worth carrying Head for the front half of the World Cup in the hope he can recover and impact at the tournament's back end.
The bad news came after another wretched day in the Australians' World Cup preparations on Sunday (Monday AEST) in Johannesburg, as they suffered another heavy ODI defeat, by 122 runs, to the Proteas in their series finale.
Head has averaged 50.66 with a strike-rate of 153.53 against the Proteas, his swashbuckling first-wicket alliance with David Warner one of Australia's key strengths.
"The time frame is still a little bit loose," Australia coach Andrew McDonald said.
"The good news is he doesn't require surgery, as it stands at the moment.
"There will be an extended period of time out and we've got to weigh up whether that time falls potentially with an option to carry him through the front half of the World Cup.
"There's no doubt he won't be available for the front half."
McDonald says Marnus Labuschagne - the series' leading run-scorer (283 runs at 70.75) - is now "likely" to be included in the World Cup squad, to be finalised on September 28.
"I can't talk on behalf of the selection panel and lock him away for the World Cup (squad of) 15 but it's no doubt looking likely," McDonald said.
"I think he's made a significant shift in his intent at the crease and putting the bowlers under pressure from where he was 12 months ago.
"There's no doubt he'll be front-and-centre when it comes to the 15-man squad later on down the track."
Player-of-the-series Aiden Markram (93) spearheaded South Africa's 9-315 at Johannesburg before Australia were blown away for 193 in 34.1 overs, paceman Marco Jansen (5-39) and spinner Keshav Maharaj (4-33) collecting career-best figures.
Australia's three successive losses in South Africa have come by massive margins of 111 runs at Potchefstroom, 164 runs at Centurion and now 122 runs at the Bullring and they've included horrific batting collapses of 8-60, 5-67 and 8-69.
"We can't afford to expose our lower-order hitters at six and seven, where we do have some power down there, too early," McDonald said.
"That happened a bit too often in this series.
"It's something we need to tighten up on.
"You can't win too many games of cricket if you're getting exposed, four, five down before the halfway mark of the innings."
Australia's World Cup preparations continue with a three-match ODI series against India, starting in Mohali next week.
