Nobody within Northern Ireland would claim that this changing of the guard has been sudden. When O'Neill returned to the job in 2022, he would have known there was little time left with those who had helped him reach such heights the first time around.

The likes of Aaron Hughes, Gareth McAuley and Chris Brunt had already retired, while Davis and Evans were still pulling on the green jersey for far longer than most would have predicted when the curtain came down on the side's 2016 campaign.

As O'Neill notes, Dallas was the only outlier having played his last international at the age of 30 before being forced to retire with a leg injury sustained when playing Premier League football for Leeds United.

"I think Stuart Dallas would easily have played until he was 35 or 36 if the injury hadn’t occurred," he said.

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

That inevitability is now a reality with Northern Ireland having to look to a new generation.

While Liverpool's Conor Bradley has been the undoubted star attraction, getting game time at Liverpool and scoring winning goals in each of his country's past two victories, players like Shea Charles, Isaac Price and Trai Hume have quickly become key figures too.

Despite finishing with victory over Denmark, the qualification campaign for Euro 2024 was disappointing, with the improved form since coming with the caveat that it was not in competitive action.

These Nations League games remain very much a precursor to World Cup qualifying starting next year, but there is no doubt that they represent an opportunity for players to show they are ready to fill the gaps left behind by vastly more experienced departed figures.

"You are just hoping you’ve got those players to step up and I suppose we will learn now," O'Neill said.

"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."

As ever for international managers, the main area of concern is outside of O'Neill's control, namely where and how often his players are seeing the pitch.

Bradley has appeared off the bench in the first three of Liverpool's games under Arne Slot but that is the only Premier League minutes for his entire squad this season.

Charles left newly promoted Southampton for Sheffield Wednesday on a season-long loan deal, while Callum Marshall will spend another year away from West Ham, this time at Huddersfield. After finally sealing a transfer out of Newcastle, there will be hope too that Jamal Lewis gets regular football at Sao Paulo.

"I think this is an exciting group of players," O'Neill said.

"They have to develop individually. The concern a little bit is where are their minutes going to come from?

"It's very difficult to come and play international if you're either not playing or your club situation is not particularly positive. I know that from my own experience."

And while O'Neill can relate to the harking back to what are now the glory days of a past generation - he came into a Northern Ireland side in 1988 that had qualified for the past two World Cups, something the country has failed to do since - he sees the Nations League as an important step in his new side's journey, especially given the dearth of competitive victories of late.

"As great a player as Jonny, and Steven and Craig and these people were, they played through a lot of times when they didn't win a lot.

"You have to go through these periods as well. This Nations League will give us the opportunity to win games against opposition that will test us."