Loose forward Rob Valetini and scrumhalf Nic White have joined the already ruled-out quartet of Andrew Kellaway, Hunter Paisami, Dave Porecki and Taniela Tupou on the injury-list following the 13-10 defeat to Ireland in Dublin over the weekend.
Valetini had been in doubt with an ankle problem, while White suffered a head-knock.
Though White passed his initial head impact assessment on game-day, his injury was subsequently upgraded, meaning a mandatory 12-day stand-down period, Rugby Australia said.
Prop Tupou will have scans for a suspected ruptured Achilles tendon, placing him in some doubt for next year's World Cup in France.
The casualties leave under-pressure coach Dave Rennie needing to re-deploy some of the fringe players who were embarrassed in Australia's first ever defeat to Italy in Florence just over a week ago.
"I can guarantee there will be guys itching for another opportunity after the Italy effort," Rennie said after Ireland.
Australia have lost three out of four matches on their northern hemisphere tour, all by tight margins.
Wales will also be desperate to finish their season on a high after their shock home loss to Georgia.
