Blair was surprisingly left out of the original party but was handed a reprieve following the injury to Ireland's O'Leary in a Celtic League match with his province Munster.

Blair will battle it out with England's Harry Ellis and Wales star Mike Phillips ­ the pre-tour favourite to be the Test scrum-half - for the right to face South Africa in June.

The 28-year-old, who was won 58 caps for Scotland, has impressed as captain of his country since succeeding Jason White.

He said: “I’m really pleased to have been given the opportunity to tour with the British and Irish Lions; it is a massive honour.

“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.

“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. I’m excited about the challenge ahead.”