The Bulls suffered a setback when flanker Deon Stegmann was ruled out of Saturday's match with the Brumbies in Canberra due to an ankle injury.
Stegmann sustained the injury in his side's 23-18 defeat to the Reds in Brisbane and will be out of action for at least a week, team doctor Org Strauss confirmed on Monday.
Bjorn Basson, who was brought back into the side for the Reds clash following an ankle injury, will only train on Wednesday, but is expected to play.
Flip van der Merwe is on the mend after missing the Reds match and should be back for the clash against the Conference topping Australians.
Wynand Olivier (knee, four weeks), Akona Ndungane (eye socket, three weeks), Dean Greyling (stress fracture, three weeks), Francois Hougaard (ankle, three weeks) and Marcel van der Merwe (knee rehab, May) are recovering back in Pretoria.