Cooper the latest Wallaby casualty

The Wallabies have suffered another blow with the news that flyhalf Quade Cooper has been ruled out of the remainder of the Rugby Championship.

Scans in Brisbane on Tuesday revealed that Cooper has a small chip of articular cartilage in his right knee which will need to be attended to.

While the injury will require an operation to clean up and is to the same knee that was operated on after last year’s World Cup, it is not a long term injury and so may not rule Cooper out of the Wallabies' year-end tour in November.

A decision on the flyhalf's availability for that trip will be made once his rehabilitation is underway.

The loss of the mercurial playmaker is the latest in a series of injury blows for the Wallabies which has seen senior players such as James Horwill, David Pocock and Will Genia sidelined already.

However, Cooper's unavailability does resolve a selection headache for under-pressure coach Robbie Deans.

Deans admitted after Australia's lucky 23-19 escape over the Pumas on Saturday that he had considered bringing Cooper off, following a series of crucial errors including a wayward kick that led to an Argentinian try.

The Wallabies were down 19-6 with 20 minutes left to play, and only two last-gasp runs over the line saved Deans from a loss that may have been terminal to his stewardship of the Australian side.

The mercurial Cooper has been under heavy scrutiny since his inconsistent performance at last year's World Cup where he was relentlessly booed by Kiwi fans over alleged cheap shots on All Blacks captain Richie McCaw.

He was not selected for Australia's first Bledisloe Cup match against New Zealand last month, and had few chances despite running on in the following match, which New Zealand snatched with a historic 22-0 thrashing.

The Wallabies depart Australia on Thursday for their September 29 Test against the Springboks in Pretoria, finishing their Rugby Championship campaign with a game against Argentina the following week.