AUSTRALIA is set to require a new batsman for the third Test in Adelaide after a devastated Usman Khawaja broke down with a left hamstring injury in dramatic circumstances late yesterday at the WACA.
It's a bitter blow for Khawaja who has endured a cursed run, but Australia also went to stumps on day two of the second Test with the added worry of New Zealand's super-bat Kane Williamson.
Khawaja ruptured his knee last summer, as well as suffering recent hamstring trouble, before triumphantly returning to the Australian side with back-to-back hundreds against New Zealand. 
However, even if scans come back positively today, it would appear West Australian duo Cameron Bancroft and Shaun Marsh are likely to be in a head-to-head shootout to be called up in Khawaja's place for the next Test.
"He's hurt himself and it's not great," said David Warner, who shared in a 302-run stand with Khawaja on day one.
"Fingers are crossed he can try and recover in the next 10 days." Khawaja could miss up to a month with the injury, according to respected sports doctor Peter Larkins, but at the very least he will be racing the clock to be fit for the day-night Test starting in just 13 days' time.
Australia made just two breakthroughs in excruciating heat yesterday, with New Zealand to resume on day three at 2/140 in response to the home side's commanding 9(dec)/559.
The Black Caps still have a mountain to climb trailing by 419 runs, but hope of keeping the series alive is not completely lost as long as unbeaten No.3 Williamson (70 not out) stays at the crease.
Warner, whose epic knock came to an end on 253, said the team's thoughts were with Khawaja but emphasised the immediate focus needed to be on a contest the opener believes will go down to the wire.
"We've got to take 18 wickets to win this Test â€¦ so it's one of those games where it will go five days and come down to the last hour I reckon," said Warner, who also bemoaned the fact balls have had to be swapped five times already this match due to poor condition.
"I think (for Usman) obviously back-to-back hundreds and running a lot out in the middle, with a quick turnaround (between games), then obviously fielding at mid-off as well and having to chase a hell of a lot of balls to the boundary, it's just not ideal." Hamstring problems have been an ongoing issue for Khawaja for the past couple of months.
It was a forlorn Khawaja who limped off the WACA yesterday with the aid of Australian physio David Beakley.
Khawaja was chasing a ball into the outfield when he pulled up lame and will go for scans in the morning.
Based on National Selector Rod Marsh's claim that youth will win out in like-for-like selection battles, Bancroft could be in the box seat for a Test debut provided selectors feel he can adjust to batting at No.3.
Otherwise they could shift Steve Smith up to No.3 and pick Marsh or even another West Australian veteran Michael Klinger .
Mitchell Starc (1/17 off 11) made an early breakthrough yesterday in extreme heat at the WACA, however, Williamson again made life difficult for the Australians making his third consecutive score of 50 or higher on the tour.Nathan Lyon chipped in with the wicket of opener Tom Latham but Mitchell Johnson (0/34) and Josh Hazlewood (0/48) struggled.