Bulls lock Paul Willemse will be out of action for three months following a knee injury sustained in Saturday's win over the Kings.
An MRI scan revealed a medial collateral ligament injury to the big lock, ruling him out of action for the next nine weeks. He will undergo an operation on Wednesday.
Meanwhile, a green light was given to the fitness of Wynand Olivier and Dewald Potgieter following their respective knee injuries.
Olivier was injured on tour and Potgieter was a late withdrawal from the side which travelled down to Port Elizabeth.
According to team doctor Org Strauss, both players would be considered for Saturday's match against the Waratahs in Pretoria.
Francois Hougaard would also train on Wednesday and, pending his fitness afterwards, could be considered for the weekend. He suffered an ankle injury.
Frik Kirsten (elbow), Deon Stegmann (ribs), Callie Visagie (ankle), Flip van der Merwe (chest muscle), Lionel Mapoe (foot) and Chiliboy Ralepelle (calves) all sat out of training on Monday, but could still be considered for selection.
Jean Cook (ankle) would also be back to fitness on Wednesday.
Hencus van Wyk (shoulder, one week), Grant Hattingh (thumb fracture, three weeks), Zane Kirchner (finger operation, three weeks) and Francois Venter (groin, seven weeks) were all still out of action but Marcel van der Merwe (knee rehab) would be back in training for the first time this year.