Of course, O'Neill would prefer if the Manchester United defender was still available, but after the 36-year-old announced his retirement from the international scene - following fellow greats Steven Davis, Stuart Dallas and Craig Cathcart out of the picture over the preceding 12 months - the Northern Ireland manager will approach the Nations League campaign in 2024 with faith that his 'new era' team can deliver strong performances and positive results.

In O'Neill's squad for September's games at home to Luxembourg and away to Bulgaria, just two Euro 2016 stars - Paddy McNair and Josh Magennis - are included. Many of the rest were still at school when that tournament was going on!

Michael O'Neill at the squad announcement ahead of Northern Ireland's Nations League double-header

What is pleasing for O'Neill is that in previous internationals, the likes of Conor Bradley, Trai Hume, Shea Charles, Brodie Spencer and Isaac Price have shown they revel in the spotlight.

"We have to continue to develop as a squad, and the players who have been around for a while have to step up and the younger ones have to realise that, going forward, they're going to be the backbone of this team," said O'Neill.

"The one thing you can't replace is experience. The only way you can do it is to keep putting the players on the pitch.

"We have a number of young players that are getting consistent game time when they come here to play international football, maybe more so than they're getting at their clubs on occasion. Hopefully, that will help them develop and they'll bring the experience and feel comfortable playing.

"With this group of players, we could play a team which would be under 24, and that's very young for international football.

"We believe that that's the right way to go, that these players will continue to hopefully develop and bring the country forward. We have to invest in them, and investing in them and giving them game time is important.

"I think this group, if they continue to grow up as they are doing together, they'll have a really strong bond and a real good team spirit, which I've seen evidence of already. There's athleticism and pace in the team. We've just got to continue to cultivate that."

During the media briefing at Windsor Park for his squad announcement - which saw recalls for Shayne Lavery and Brad Lyons - while speaking about the future, O'Neill paid a warm tribute to Evans who, after 107 caps and numerous outstanding displays, is now a past international ready to focus on United in the 2024/25 season after earning a one-year contract extension at Old Trafford.

"Jonny's a top-class player and top-class individual to have in any squad, any team. The fact that Manchester United still value him as they do is a testament to that as well," said O'Neill, who hasn't included Portsmouth's Paddy Lane in this squad.

"It's disappointing (he is retiring from international football), but it's not something we haven't discussed. We've discussed it over the last six months every time we've caught up.

"He never really wanted to make that decision, but I think he realised to give himself a chance of making a real impact at Manchester United, it meant that the international breaks would probably help physically.

"He's a lot of commitments, three young kids as well. International football, when you've been doing it for 18 years, it's a big commitment. But in terms of what he's brought, what he's given us over the years, has been fantastic."

Northern Ireland manager Michael O'Neill believes the younger players need to step up as older heads depart the scene

O'Neill added: "I always try to keep the players playing as long as possible.

"You look at Aaron Hughes and Gareth McAuley, guys who played late into their 30s, you always try to make those players feel valued. That's no different to Jonny.

"You look over the last 12 months, with Jonny now going and losing Steven Davis, Stuart Dallas, Craig Cathcart (to retirement) and we've also lost Corry Evans (to injury) - you're talking around 500 caps there.

"I knew with Jonny, it was coming. I wouldn't have wanted it to happen. I thought when I came back in (as Northern Ireland manager), there was another campaign in this group of players but, unfortunately, mostly because of injury, we were deprived of that.

"It is always sad to see someone like Stuart particularly because his career has been taken from him right at his peak. I think Stuart Dallas would easily have played until he was 35 or 36 if the injury hadn't occurred.

"With the other players, Steven was 39 and Jonny will be 37 in January, so there was an inevitability about it.

"You are just hoping you've got those players to step up, and I suppose we will learn now. What we saw in the last campaign, though it was difficult, was the emergence of a new team coming through, and that's what we have to work with. We have to continue to believe and give the boys as much exposure as possible," commented O'Neill, referring to the future again.

The former Stoke boss said he wouldn't be naming a permanent successor as captain to Evans just yet but was clear that he wanted to maintain the fine run of form in which Northern Ireland have beaten Denmark, Scotland and Andorra and drew in Romania. The only loss in the last five games was away to Spain, who then went on to win Euro 2024.

The match versus Luxembourg on September 5 is the first home one since November 2023 when the Danes were defeated.

"In the last four or five games, we've been able to pick a more consistent team, and I'd like to continue to do that so that players are building relationships and partnerships," said O'Neill.

"It's nice to play again at home and let the people see young Northern Ireland players and see that something good is happening and that we will continue to develop, giving us some great nights to look ahead to."