Wallabies fullback Israel Folau has been ruled out of Saturday's Test against South Africa with an ankle injury.

The fullback injured his ankle against the All Blacks in Sydney's Bledisloe Cup opener and missed the Wallabies' Auckland Test with the issue.

He was on track to return to the Wallabies side in Brisbane but pulled up sore on Saturday morning and pulled out of the clash against the Springboks.

Folau's 11th-hour withdrawal is the second major blow for the Wallabies after flanker David Pocock was ruled out with a neck injury on Friday.

Dane Haylett-Petty will move to fullback with Jack Maddocks on the wing and Tom Banks will come into the 23.

Folau's absence will only intensify the pressure on the Wallabies in a must-win clash against the Springboks in Brisbane.

The Wallabies have won just one of their five Tests this year and sit last in the Rugby Championship after two rounds.

The Wallabies take on South Africa on Saturday September 8, kicking off at 8pm AEST, LIVE on FOX SPORTS, Channel Ten, Macquarie Radio and RUGBY.com.au RADIO. Buy tickets here.

TEAM

Wallabies to face South Africa

1. Scott Sio (47 Tests)

2. Tatafu Polota-Nau (84 Tests)

3. Allan Alaalatoa (25 Tests)

4. Rory Arnold (15 Tests)

5. Adam Coleman (25 Tests)

6. Lukhan Tui (9 Tests)

7. Michael Hooper (c) (84 Tests)

8. Pete Samu (5 Tests)

9. Will Genia (92 Tests)

10. Kurtley Beale (76 Tests)

11. Marika Koroibete (13 Tests)

12. Matt Toomua (35 Tests)

13. Reece Hodge (29 Tests)

14. Jack Maddocks (2 Tests)

15. Dane Haylett-Petty (23 Tests)

Reserves

16. Folau Faingaa (1 Test)

17. Tom Robertson (23 Tests)

18. Taniela Tupou (4 Tests)

19. Izack Rodda (9 Tests)

20. Ned Hanigan (13 Tests)

21. Joe Powell (4 Tests)

22. Bernard Foley (60 Tests)

23. Tom Banks (1 Test)