18 May, 11:09
IRFU Chief Executive Philip Browne has issued a statement following confirmation of Ronan O'Gara's decision to retire from playing professional rugby.
"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.
"The selectors and I have had plenty of time to review the situation in terms of a replacement scrum half and were in agreement that Mike Blair should replace Tomas.
"Mike was on our reserve list for such an eventuality. He is an excellent addition to the British & Irish Lions squad.
"As a national captain he is well respected by his peers and his 58 Tests for Scotland mark him as a very capable and experienced scrum half," he added.