Conor Murray was the surprise choice to replace Alun Wyn Jones as British and Irish Lions captain for the tour to South Africa.
The Lions suffered a devastating blow as Jones was ruled out of the tour after dislocating his shoulder in the 28-10 victory over Japan at Murrayfield on Saturday.
Murray is a leftfield appointment by head coach Warren Gatland but he is a veteran of two previous Lions tours and has amassed 89 caps for his country.
The 32-year-old Ireland scrum-half started against Japan and is favourite to form a half-back partnership with Dan Biggar for the Test series.
The Lions also learned that Justin Tipuric will not be travelling to South Africa because of a shoulder injury.
As two Wales forwards are ruled out, two more are brought in as their replacements with Adam Beard and Josh Navidi now set to depart with the squad on Sunday night.
Beard and Navidi have been regular starters in the Welsh pack in recent times including this year’s Six Nations.
Murray has beaten more vaunted Lions captaincy contenders such as Maro Itoje and Owen Farrell to the post.
“We’re all incredibly disappointed for Alun Wyn and Justin. The timing of these injuries seem particularly cruel given we fly to South Africa tomorrow, but unfortunately they’re part of the game,” Gatland said.
“Alun Wyn will obviously be a big loss, both on and off the field, but will be ably replaced by Conor.
“Conor is an outstanding rugby player and is held in the highest regard with both the players and coaches.
“As a three-time Lions tourist, he knows what will be required as captain and I’m certain he will lead the squad with excellence. He will also be well supported by an experienced leadership group.
“We plan for Adam and Josh to join up with the touring party before we depart for South Africa tomorrow evening.”
Jones departed just eight minutes into the match after being hurt during a ruck clear-out by James Moore, and although he returned to the field to be with his team-mates at the final whistle, the Lions’ worst fears had already been realised.
After the game, Gatland had said: “His shoulder dislocated. We’re getting it scanned but it’s looking like we’ll have to replace him.
“It’s very disappointing. He’s been around rugby long enough but he’ll be gutted.
The challenge now facing Gatland is to prevent the dire setback of losing Jones, a veteran of four Lions squads, from affecting morale.
“No one is in shock because if you’re in shock its reflects back into the whole squad,” said the Kiwi, who revealed that number eight Jack Conan carried a hamstring injury into the game.
“We understand things are different and fluid and we have to move on and be able to react and make decisions and that is the only way you can deal with it.
“If you go into a shock scenario and look as if you are panicking then it will reflect badly on us.”