Blair captained Edinburgh to a win over Newport Gwent Dragons on Saturday
Scotland captain Mike Blair has been called up to the British and Irish Lions squad to replace injured scrum-half Tomas O'Leary.
The 28-year-old has been promoted from the reserve list after O'Leary suffered a broken ankle when playing for Munster against the Scarlets on 24 April.
"I'm really pleased to have been given the opportunity to tour, it is a massive honour," he said.
"Mike is an excellent addition to the squad," head coach Ian McGeechan added.
"As a national captain he is well respected by his peers and a very capable and experienced scrum-half."
Blair's countryman Chris Cusiter, Welshman Dwayne Peel, England's Danny Care and Ireland's Peter Stringer were also thought to be in the frame to replace O'Leary.
Blair's initial omission made him one of three national team captains to be left out along with England's Steve Borthwick and Wales' Ryan Jones.
But he has remained confident after overseeing a run of form that has carried Edinburgh to third place in the Magners League.
"The call-up just goes to show how quickly everything can change in rugby and I'm determined to seize my chance and make an impact," he said.
"Since the original squad was announced, I've just focused on playing well for Edinburgh and helping the team climb up the Magners League and fortunately that has helped me to get selected."
Edinburgh coach Andy Robinson, who toured with the Lions as both a player and a coach, fully endorsed his captain's selection.
"Mike has matured into an outstanding leader, for both Edinburgh and Scotland, and he is an intelligent player with a lot to offer the Lions selectors," he said.
The addition of Blair to the party takes the Scottish contingent to three players, with prop Euan Murray and second-row Nathan Hines already travelling.
O'Leary is stretchered off against Llanelli
Leicester's Harry Ellis and Ospreys' Mike Phillips will compete with Blair for the Test number nine shirt.
McGeechan still has to decide on a replacement for injured Wales centre Tom Shanklin, who will take the summer to recover from a dislocated shoulder.
England duo Mike Tindall and Delon Armitage, plus Ireland's Gordon D'Arcy, are thought to be leading the race, although there have been some calls for Gavin Henson to be reconsidered as he recovers from injury.
Jamie Noon and James Hook are other outside bets, while Max Evans' hopes of expanding Scottish representation further were extinguished after he damaged knee ligaments over the weekend.
McGeechan is also awaiting a fitness update on Jamie Roberts, who aggravated a shoulder injury playing for Cardiff Blues against Munster on Sunday.
He may need to make a further change to his original squad depending on the outcome of Munster flanker Alan Quinlan's disciplinary hearing on Wednesday.
McGeechan prefaced his announcement of Blair's selection with sympathy for O'Leary.
"Sport can be very cruel. One minute Tomas was celebrating his well-earned call-up to the Lions tour to South Africa, the next he is being carried off injured.
"Unfortunately the injury was a serious one and it ruled Tomas out of the tour. We wish Tomas all the very best for a quick recovery."