Matthew Wade and Mitchell Marsh have been called up as cover to join the Australia squad after Usman Khawaja and Marcus Stoinis emerged as fitness doubts ahead of their World Cup semi-final against England*. Khawaja and Stoinis had sustained injuries during Australia's defeat to South Africa at Old Trafford on Saturday.

Wade and Marsh were originally part of the Australia A squad that's touring the UK and is scheduled to play a four-day game against Sussex starting Sunday. The two players left Brighton on Sunday morning for Birmingham, where Australia play the hosts on Thursday.

Both Wade and Marsh come on the back of fine one-day form. While Wade scored centuries - 155 and 117 - before his 42 and 41 in Bristol last week, Marsh has been unbeaten all four times he has batted on the A tour so far, that includes a half-century when he also took 3 for 43 against Gloucestershire.

On Saturday, Khawaja retired hurt on 6 with what was subsequently described as a "hamstring strain" by a team spokesperson and will undergo a scan on Sunday. His captain, Aaron Finch, admitted he was not especially optimistic about the outcome.

"It doesn't look ideal for Usman," Finch said. "He'll have a scan tomorrow and if we need a replacement - and I think we will - but until you get the definitive scan it's hard to know. But it's not looking great for him, in all honesty. He's done a couple of hamstrings before and he said it feels a bit similar."

Australia's other concern is over Stoinis, who clutched his right side after throwing a ball in from the boundary and only bowled three overs. He then received treatment while batting and was run-out when it appeared he was unwilling - or unable - to stretch and dive when called through for a sharp run by his partner, David Warner.

Stoinis had previously suffered an injury to his other side earlier in the tournament. He, too, will undergo scans on both sides on Sunday.

"Marcus is just a bit sore in his side," Finch said. "We'll have to wait for the scans."

Australia have already lost Shaun Marsh in recent days. Marsh was hit by a delivery from Pat Cummins while batting in the nets and subsequently diagnosed with a broken arm. Peter Handscomb has joined the squad as his replacement.

Watch on Hotstar (India only) - David Warner's 122

There was some silver lining in losing to South Africa. Had Australia won, they would have been obliged to play in the first semi-final on Tuesday. As it is, defeat means they have to play in the second semi-final on Thursday, giving their players slightly longer to recover.

But it was something of a surprise when Khawaja returned to complete his innings after Australia lost their seventh wicket. Their pursuit seemed almost hopeless at that stage - they required 51 runs off 28 balls - and Khawaja ran the risk of exacerbating the injury. As it was, he added another 12 runs and was unable to pull off an unlikely victory.

ALSO READ: Du Plessis leads South Africa to consolation victory

"He didn't aggravate it," Finch said. "It didn't work out the way we planned, but he put the team first, which is a great quality to have. He was more than happy to go back out."

The desperation Australia showed in the final moments of the match, however - not least in sending Khawaja back out to bat - and the disappointment they showed in defeat did suggest they would have rather played in the first semi-final. Not only would that have avoided the need to travel - the first semi-final is in Manchester, where Australia have been based for some time - but they would have faced New Zealand who would appear to be, according to the rankings at least, the weakest of the four teams left in the competition.

As it is, Australia will face the No. 1-rated hosts at Edgbaston, where England have won their last 10 international games.

*0855 GMT: The story was updated after an update from Cricket Australia