South Africa captain Adriaan Strauss underwent back surgery on Thursday and like Springbok winger Ruan Combrinck will miss the start of next year’s Super Rugby competition.
Strauss returned from South Africa’s disappointing November tour of Europe with a pinched nerve in his lower back and was recommended an operation to fix it.
The 31-year-old hooker is now expected back in action for the Bulls in March, officials said on Friday.
Strauss announced his retirement from international rugby after a year as captain in which South Africa lost eight of 12 Tests this year but has committed to playing for the Bulls for the foreseeable future.
Combrinck, 26, fractured a shoulder joint playing for South Africa against Wales in Cardiff last Saturday and underwent surgery on Wednesday.
He will be out for around four months, a statement from the Lions rugby franchise.