Usman Khawaja has been ruled out of Australia's Cricket World Cup semi-final showdown with hosts England on Thursday.

Khawaja and Marcus Stoinis had scans after suffering respective hamstring and side injuries in the defeat to South Africa at Old Trafford.

Matthew Wade and Mitchell Marsh were called up as cover from the A squad earlier on Sunday ahead of their four-day match with Sussex.

Australia coach Justin Langer is uncertain on Stoinis' chances of facing England at Edgbaston but says Khawaja's World Cup is at an end, with Wade to replace him in the squad once the necessary paperwork is completed.

"It's such a pity for [Khawaja], for someone who's been so integral to how we've been playing," he said. "Like Shaun [Marsh, who broke his arm on Thursday] I feel that sad for him that he's going to miss the World Cup semi-final.

"Matthew Wade is coming up, he's in great form, he's had a great 12 or 18 months back home but he also just scored two hundreds [for Australia A] so he's in great nick.

"Mitch Marsh is going to come on standby for Marcus Stoinis just to see how he comes up… If they have to come in they'll be ready to step up."