Rory Best has been called into the British and Irish Lions squad to tour Australia after
Dylan Hartley received an 11-week ban from the RFU on Sunday.
Ulster hooker Best will join up with the Lions squad on Monday.
Hartley was suspended after being found guilty of verbally abusing referee Wayne Barnes in the Premiership final.
A final decision on Hartley's participation in the tour will be dependent on the outcome of any potential appeal by the England hooker.
Best's initial omission from Warren Gatland's 37-man party for the tour to Australia had been something of a surprise.
Gatland admitted after the squad announcement at the end of April that leaving out Best had "probably been our hardest decision".
Welshman Richard Hibbard and England's Tom Youngs are the other two hookers in the squad, which will travel to Hong Kong on Monday evening ahead of Saturday's game against the Barbarians.
The addition of Best brings the Irish representation in the squad to 10.
"It was hard when I didn't make the initial squad because it is everyone's ambition to play for the Lions, but to be selected now is a massive honour," said Best.
"To be finally selected makes playing professional rugby worthwhile and makes up for the feeling I had a few weeks ago when I thought the chance had gone."
"With uncertainty over the availability of Dylan Hartley to tour, and with the first of 10 matches only days away we had no option but to call up the additional player," said Lions Tour manager Andy Irvine.
"Despite the circumstances we should congratulate Rory, who will join the squad tomorrow and fly with us to Hong Kong."
The Lions will play 10 matches, with the first Test taking place in Brisbane on 22 June.