The Bulls have revealed that scrumhalf Piet van Zyl sustained a knee injury in their 19-12 loss to the Waratahs and he will not play against the Western Force.
Pretoria-based Super Rugby franchise the Bulls have one match left on thier 2014 Super Rugby tour which is against the Western Force in Perth on Saturday.
Van Zyl left the field against the Waratahs in Sydney last weekend and will be out of action for two weeks, Bulls team doctor, Org Strauss, said on Monday.
The Bulls did however get some good news as both Akona Ndungane (knee) and Jurgen Visser (foot) have been declared fit to face the home side in the nib Stadium.
Ndungane's availability will result in Francois Hougaard moving back to the base of the scrum.
The Bulls are also awaiting the result of Flip van der Merwe's citing, as this will determine his availability for the match.