London - Greig Laidlaw will captain Scotland in their opening November international against Argentina at Murrayfield this weekend, coach Vern Cotter has announced on Tuesday.
Edinburgh lock Grant Gilchrist had been due to lead the side during this month's internationals at home to Argentina, world champions New Zealand and Tonga.
But the 24-year-old was ruled out of the November campaign after suffering a fractured arm playing for Edinburgh in their European Challenge Cup win over Lyon -- just four days after he'd been told he would be captaining his country.
Laidlaw, now with English Premiership side Gloucester, has led Scotland on seven previous occasions, including Kiwi coach Cotter's first Tests in charge against the United States and Canada in June.
The 31-year-old scrum-half, the nephew of outstanding Scotland No 9 Roy Laidlaw, also captained Edinburgh for three seasons before moving south to join Gloucester in pre-season.
"Obviously we're disappointed for Grant, who misses the opportunity to captain his country at home on this occasion, however congratulations must now go to Greig who takes on that responsibility for this Saturday's game," said Cotter in a Scottish Rugby Union statement.
"Greig offers us a bit of continuity, having captained the side on the summer tour. He's been playing well for Gloucester and I think he deserves this selection.
"He offers us a combination of good tactical nous and good leadership. He's an exceptionally competitive player and everyone respects his desire to win, to drive Scotland forward and perform well."
Cotter also said that 22-times capped Edinburgh No 8 David Denton had been added to Scotland's squad.
Denton last played for Scotland against Wales in the Six Nations in March and then missed the off-season tour with concussion.
A hamstring injury sidelined Denton for the first seven weeks of the current campaign before he returned to club action against Lyon.
Scotland edged out Argentina 21-19 when the teams last met, in Cordoba in June.
Both sides are due to name their teams for this weekend's Test on Thursday.