Bulls flanker Dewald Potgieter has been ruled out of action for six months after surgery on a torn bicep.
Potgieter, who has six caps for South Africa, was injured in a defeat at the Wellington Hurricanes a fortnight ago.
He flew back from New Zealand for the operation along with team-mate Deon Stegmann, who will undergo an operation on a groin injury next week and could be out for up to four months.
Potgieter, 27, only returned to the Bulls in March after spending six months playing in Japan.
Potgieter and Stegmann join Pierre Spies, Arno Botha and Frik Kirsten on the club's long-term injury list.