Experienced scrum-half Greig Laidlaw will captain Scotland in Saturday's autumn Test against Argentina following an injury to Grant Gilchrist.
Gilchrist had been chosen as new coach Vern Cotter's skipper but the 24-year-old Edinburgh lock was ruled out of the series with a broken arm.
Laidlaw, who left Edinburgh for Gloucester in the summer, has led Scotland on seven occasions previously.
"Greig offers us a bit of continuity," Cotter said.
"Obviously we're disappointed for Grant, who misses the opportunity to captain his country at home on this occasion but congratulations must now go to Greig, who takes on that responsibility for this Saturday's game," the New Zealander said of the 29-year-old.
"He offers us a combination of good tactical nous and good leadership.
"He's got experience, he reads the game and communicates well with his team-mates, so his appointment is due to a combination of factors.
"He's an exceptionally competitive player and everyone respects his desire to win, to drive Scotland forward and perform well."
Meanwhile, Cotter also confirmed Edinburgh number eight David Denton, who has been capped 22 times, has been added to the Scotland squad.
Denton last played for his country against Wales in the Six Nations in March, having missed the summer tour with concussion.
A hamstring injury sustained in pre-season then kept him out of the first seven weeks of this season before he returned to action in his club's 25-17 win over Lyon in the European Rugby Challenge Cup last month.