Wilhelm Steenkamp and Dean Greyling have both been ruled out of the Bulls' Super Rugby clash against the Stormers on Friday.
The former is expected to be out of action for a further two weeks with a joint injury, while Greyling is still recovering from a stress fracture to his foot, which he suffered in pre-season.
Dawie Steyn has returned to the squad, but is not expected to start as he continues his recovery from a leg fracture, but Louis Fouche is available after injury.
The Bulls finished the last Super Rugby campaign in fifth position.
