Significantly, Warren Gatland has been impressed by O'Mahony's "Munster mongrel" warrior spirit during the tour, and it may be enough to convince the Lions head coach he is the right man to lead the Test side - despite only captaining Ireland on three occasions.
"I think sometimes that you're looking, it's not something that you can quantify what Munster brings to a game," Gatland when he appointed the flanker as captain to face the Maori side.
"It's a special pride, sometimes the performances they can produce, it's done consistently over the years. Being able to dig deep and bring performances from places where individuals and collectively people often can't do. That's what Peter will bring to the team."
There remains an outside chance that Warburton may yet be promoted to the side, possibly even in O'Mahony's position at six given O'Brien's outstanding form against the Maori side. Alun Wyn Jones is another contender, having captained the Lions in their victory over the Crusaders but it all but certain that the starting locks will now be Maro Itoje and George Kruis.
Owen Farrell, who will start at fly-half having shaken off his quad injury, could also come under consideration but with little experience of captaincy on the Test stage, Gatland may decide the Saracens fly-half already has enough responsibility in running the game to be burdened with leadership duties.
Meanwhile Farrell senior has fired a warning to the All Blacks, claiming the Lions were ready to "take ourselves to a place individually we've not been to before" in a rallying call similar to his famous "hurt arena" speech to the players ahead of the third Test against Australia in Sydney four years ago.
"It's going to be a hell of a game," said Farrell. "I know we'll turn up and we're a good side brimming for a big challenge. Mentally and physically we'll be ready. It'll be interesting to see how the two teams marry together, the chemistry of that, who adapts well on the run.
"That's what the All Blacks have been very good at over the last period of time. We've got to be aware of that.
"Physically I don't think we've disappointed so far. Will we need to up our game? Certainly we will do. I think we're going to have to take ourselves to a place that individually we've not been to before. But the boys realise that and are excited by that challenge."
"I think the game has cranked up (since 2013). The All Blacks have certainly got better over the last four years and are reigning supreme at this moment in time. We've got to get close to that, haven't we?"
Asked if Farrell felt the Lions would have enough defensive firepower to put this All Blacks side under more pressure that they had ever experienced before, he added: "Hopefully, but there's no doubt that they'll be saying the same thing and again it's who balances that out well in the heat of the battle, isn't it? Who deals with the pressure best, who deals with the situation and makes the best decisions on the run.
"We feel that we've got a game and the players to play in all sorts of ways.
"We have to be careful this week of not overcoaching. We've got to be careful of making sure that the plan is crystal clear for them, so they can be on point come Saturday and already it's been great that we've had a few days already to get some basic stuff in them through the week and we've got to get that right.
Come Thursday, Friday it will be over to the players and we've got to make sure that their heads are crystal clear on who they're going to go about this game."
