After losing the physical battle to the Kiwis in the 30-15 defeat at Eden Park, Gatland has beefed up his breakdown forwards by also bringing Maro Itoje into the second row in place of Saracens and England team-mate George Kruis.

Gatland took O'Mahony to one side to explain his decision before announcing the team to his players on Thursday morning, overnight Irish time, telling the Corkman to keep his chin up and concentrate on trying to reclaim his place for the third and final Test on July 8.

“It was a tough call,” the Lions bos said. “We looked at that and felt it was an opportunity to bring in Sam and Maro who both made an impact off the bench last week. We need to get some pressure on the ball and that’s something Sam is excellent at doing and he has got some rugby under his belt now.

“We could have put Peter on the bench and we had a long discussion about that, but CJ Stander has had an outstanding Six Nations and was good the other night with his carries and his physicality, so the impact he is able to bring off the bench could be significant.

“Look, Peter has been very unlucky. He has done a great job for us in terms of the games he has been involved in and the captaincy. He’s unlucky enough that we can have got choices and can make changes and use different combinations.”

There are also attack-minded changes from the Lions, with Ireland fly-half Johnny Sexton starting in the number 10 jersey with Owen Farrell, who started there last Saturday, moving to inside centre.

Gatland believes pairing the fly-halves Johnny Sexton and Owen Farrell in the Lions backline gives his side more attacking options against the All Blacks than an orthodox 10-12 partnership.

Yet while the changes to the pack have been made as a response to the All Blacks' physical dominance at the breakdown – both Stander and abrasive lock Courtney Lawes have been added to the bench - selecting Farrell at inside centre has arguably sacrificed the defensive intensity that Ben Te'o brought in Auckland against opposite number Sonny Bill Williams.

Te'o has been dropped to the bench to accommodate the Sexton-Farrell 10-12 pairing with the Lions management confident it can get them on the front foot in their bid to save the series.

“From an attacking perspective, I think it's giving more of an attack option with that combination,” Gatland said overnight on Thursday. “It's just giving us two ball players and two kicking options on the right foot at first and second receiver, as well as left-foot options with Jonathan Davies (at outside centre) and (left wng) Elliot Daly. We're happy with the mix.

"One of the concerns we do have is the weather on Saturday night and we may have to change tactically how we play and then we've defensively got to do a job on Sonny Bill Williams.

"He came pretty direct against us and got a good couple of offloads away, so it's important that we shut him down. We allowed him a bit too much time on the ball last week.

“I can't remember Sonny Bill passing the ball in the game (in fact he passed seven times), but he got some good gainline for them and got a couple of offloads away, got them some front-foot ball.

“We need to make sure that our linespeed in terms of stopping that doesn't allow him to be as effective as it was. We've been working pretty hard on that this week.”

There was more bad news for Ireland supporters on Thursday when the Lions confirmed that centre Robbie Henshaw had been ruled out of the tour with a torn pectoral muscle, injured in the first half of the tourists' 31-31 draw against the Hurricanes on Tuesday.

Leinster could well be without the Ireland star for the start of the new season, with Henshaw returning home to undergo surgery. He will be leaving New Zealand alongside George North after Saturday's Test, the Wales wing having torn a hamstring in the same game.

“It’s unfortunate with Robbie with that pectoral muscle which has put him out,” Gatland said. “He is heading back to Ireland and has an operation on Monday and George with the hamstring. It’s unfortunate for him and his tour is over as well.

“We have been very lucky that we haven’t had too many injuries so far. It’s been unfortunate for those two players who have picked up injuries this week. They have been great for the squad on tour and we wish them both a speedy recovery.”

New Zealand: I Dagg; W Naholo, A Lienert-Brown, SB Williams, R Ioane; B Barrett, A Smith; J Moody, C Taylor, O Franks; B Retallick, S Whitelock; J Kaino, S Cane, K Read – captain.

Replacements: N Harris, W Crockett, C Faumuina, S Barrett, A Savea, TJ Perenara, A Cruden, N Laumape.

British and Irish Lions: L Williams; A Watson, J Davies, O Farrell, E Daly; J Sexton, C Murray; M Vunipola, J George, T Furlong; A W Jones, M Itoje; S Warburton – captain, S O'Brien, T Faletau.

Replacements: K Owens, J McGrath, K Sinckler, C Lawes, CJ Stander, R Webb, B Te'o, J Nowell.

Referee: Jerome Garces (France).