Scotland captain Jason White will miss the summer tour of Argentina after it was decided the back-row forward requires knee surgery.
Scrum-half Mike Blair is likely to continue as skipper having deputised in this year's RBS 6 Nations when the Lions forward suffered concussion.
A serious knee injury prevented Sale flanker White from taking part in the 2007 RBS 6 Nations and he only returned in time for the World Cup last autumn.
Scotland will play two Tests against the Pumas - on 7 June in Rosario and a week later in Buenos Aires.
White has played for his club Sale in recent weeks but missed last Friday's European Challenge Cup semi-final win over Bath.