Siya Kolisi will have knee surgery in Cape Town on Friday. The 31-year-old suffered a partial rupture of the anterior cruciate ligament.
South Africa will begin the defence of its world title against Scotland in Marseille on September 10, and will then meet Ireland, Romania and Tonga in Group B. The 2023 Rugby World Cup will be held in France and takes place from 8 September-28 October. The Springboks are defending their title for the first time in their history.