Wallaby playmaker Stephen Larkham is out of the World Cup until at least the quarter-finals after aggravating a knee injury while skipper Stirling Mortlock sustained a partial shoulder dislocation in Australia’s win over Wales.

Larkham, who injured his knee while kicking during training last Friday, missed the clash with Wales on Saturday and will also be unavailable for the pool matches against Fiji and Canada.

"It appears as though Stephen has aggravated a previous injury but he'll get an (arthroscopy) within the next couple of days to determine the extent of it," Wallaby coach John Connolly said this weekend.

"If all goes well it's possible he could get back (in time) for the quarter-finals but it's hard to say at this stage."

Larkham is in his final year of international rugby and Connolly says his loss is a big blow to his side.

"Obviously we lose quite a lot of experience and the players around (Larkham) are so used to having him there," he said.

Meanwhile, skipper Mortlock sustained a partial dislocation of his shoulder during his side's 32-20 World Cup win over Wales on Saturday.

Mortlock suffered the injury while scoring his side’s second try five minutes before halftime and then sat out the entire second half at the Millennium Stadium.

"In scoring that try I subluxed (partially dislocated) my shoulder but it pretty much went straight back in and soon as it did that I was fine," Mortlock said.

"If that was a quarter-final or semi-final there is no way I would have come off.

"It was more of a precautionary measure and we'll assess it over the next few days. I'll have treatment and see how it heals up."

Mortlock is due to be rested for Australia's next Pool B encounter against Fiji on September 23.