His latest setback comes after Quade Cooper's fractured scapula, which will put the Wallabies five-eighths out for the next eight weeks and is likely to force coach Richard Graham to turn to second-choice halfback Nick Frisby.
But in a rare sliver of good news for the Reds, Rob Simmons has overcome a shoulder nerve injury and will return against the Bulls.
Western Force skipper Matt Hodgson will wait at least one more week before making his comeback.
Hodgson hasn't played since tearing his hamstring in a pre-season game, and the Force have decided against rushing him back for tomorrow's clash with the Cheetahs.
The 33-year-old has returned to full training and is in line to play in next week's home game with the Stormers.
Hodgson's return can't come soon enough for the Force, who are in 13th spot after a six-match losing run.
- AAP