Bulls duo Lood de Jager and Lizo Gqoboka have been ruled out of the June Test series against England after suffering injuries in the recent match against the Sharks.
De Jager will be out for at least four months with a torn pectoral muscle, meaning he will miss the four Tests in June and perhaps the Rugby Championship.
Gqoboka has been ruled out for the rest of the year with a tendon injury in his toe, adding a headache for Bulls coach John Mitchell, with fellow prop Pierre Schoeman still suspended.
The Boks may be without their two first-choice locks this June. Eben Etzebeth is still recovering from a serious shoulder injury and is unlikely to face England.
Both Gqoboka and De Jager were part of the recent national alignment camps.