Lions and Bok centre Rohan Janse van Rensburg will undergo an operation on Friday and will be out for approximately 12 weeks.
Janse van Rensburg was injured in the Super Rugby match against the Stormers in Cape Town on Saturday.
The Lions revealed in a statement that he has a lateral collateral ligament tear and posterolateral corner injury.
The injury has ruled Janse van Rensburg out of the Springboks’ Test series against France in June.
Janse van Rensburg made his Springbok debut against Wales during last year’s end-of-year tour.
The 22-year-old has 17 Super Rugby caps for the Lions.