Toomua in doubt for Springboks, Puma Tests

Wallabies centre Matt Toomua could be ruled out of the rest of the Rugby Championship as he struggles to overcome a concussion.

Toomua received a head knock in the opening Bledisloe Test against New Zealand, his fourth concussion in the past three years.

He will miss next month's Tests against South Africa and Argentina according to a News Corp Australia report and could struggle to be fit for the return clashes in October.

Toomua's history of head knocks includes two in successive Tests in 2014, forcing him to miss more than a month of action.

The 26-year-old's current absence is likely to see coach Michael Cheika stick with Quade Cooper and Bernard Foley as the team's playmakers for the upcoming Tests.

Fellow centres Matt Giteau and Rob Horne have also been ruled out for the rest of the competition with ankle and shoulder injuries respectively.