Bulls trio Wynand Olivier, Francois Hougaard and Akona Ndungane will be returning home due to injuries sutained in the loss to the Crusaders.
Olivier (knee, four weeks), Hougaard (ankle, two weeks) and Ndungane (cheekbone, four weeks) will be replaced on tour by Francois Venter, Ruan Snyman and fit-again Bjorn Basson.
The Bulls are in Brisbane to play the Reds this weekend and have another match in Australia in a fortnight, when they face the Brumbies in Canberra.
Flip van der Merwe (chest) is also doubtful for the Reds clash, whilst Grant Hattingh suffered a knock against the head and will not train early in the week. Lionel Mapoe and Dewald Potgieter will also be fit for selection this week
Apart from the touring squad, the recovery of Dean Greyling and Marcel van der Merwe is on track.
Van der Merwe will be ready to return to the playing field in May and Greyling could be back in three weeks.