It’s an opportunity to make history by winning a series in South Africa. They don’t come often and another won’t come for years. The Springboks are reigning world champions to boot. How often will that added bonus be included?

“Unfortunately, we were all out at semi-final level in the URC, but it gave us a nice week to get organised and hit the ground running. We got into camp a little bit earlier than would,” O’Mahony said on a sunny afternoon in northern Johannesburg.

“I think it would be wrong or strange if you didn't stand up a little bit taller when you walk into this Ireland camp.

“It's a great environment, a great place to be and it’s funny any of the niggles, the sore bits fade away in this environment because of what it means to you, because of the group and who you're being coached by.

“You would see guys after the few days, guys have been beaten but they've dusted themselves off and we've an unbelievable pep in our step going training, enjoying each others’ company and as I said it's an unbelievably energised group.

“It's going to take probably our very best performance of this group's lifespan to win over here, but we've ticked off a lot of big occasions and that's why you play the game for Test matches and opportunities like this.

“It's very exciting.” The captain has fully endorsed Osborne and Casey’s selections, as he would, backing both to seize the chance against the Boks in front of a hostile 52,000 crowd in Pretoria.

“I've been lucky enough to track Craig's progress since he was a young fella, coming into Munster's setup,” O’Mahony said.

“I think from day one he's been an incredible source of energy, source of enthusiasm, professionalism, hunger, all those things you see from him on the pitch.

“Seeing his development with the way he’s gone, really taking a hold of games with his half-back partners and controlling games well, learning to be calm while big games are unfolding.

“I think the progress he's made over the last six or 12 months has been huge as well. The experience he's taken from being in camp and having some Tests, and playing a lot for Munster has accumulated for him really tidying up his game and becoming a very complete footballer, a complete scrum-half.”

And as for Osborne’s selection, out of his usual position of centre, the skipper dismissed the notion that it was a surprise.

“He’s a very patient and very understated kid,” O’Mahony said.

“Obviously been delivering incredibly well for Leinster over the past how many seasons. One of the lads presented his jersey to him last night and said it wasn’t a case if, but when, his cap would come.

“He wants to learn, he’s a top-class professional at an early age. No one in our squad was shocked that he was selected.

“It (being around the squad for some time) helps usually. Andy (Farrell), over the years has named squads and brought guys in and out at different times to gain experience and that will stand to Jamie. He’s been in a good few times now and spent a lot of time with us.

“It just makes you more familiar with guys and more comfortable. You play for something more when you know people better.

“He’s been around long enough now to know it really matters to us. Obviously it matters to everyone when they play for Ireland, but playing for the group alongside you means a huge amount.

“He’ll have had a great feeling of support from us over the last few days certainly but also since he’s come into camp.” Bok captain Siya Kolisi, who is based in Paris with Racing 92, said that the feeling in his team’s camp was different to any other squad he has been part of.

“The training here has been really good. I’m excited because there’s a new coaching staff,” Kolisi said. “The gameplan is different so it feels like I’m doing something new again. I’m excited to learn.

“It just feels different when you are in the Springboks group. It’s difficult to explain. It’s the group of people, the coaches and just the mentality.

“The purpose part of it is something as South Africans we take for granted. But once you come home from another country, some of the things you play for, that’s what I miss the most.”