While Europe’s bigger nations have their own in-house resources, countries like Northern Ireland share staff with clubs, which can bring its own challenges in an extended window.

“We don’t carry full-time doctors, full-time physios and full-time sports scientists,” O’Neill added.

“Other countries are the same, but all our staff work at clubs and we need agreement from the clubs.

“That’s a challenge to be able to staff it properly and keep the level of professionalism.

“The big countries don’t have that, they have full-time staff and an army of staff to be able to do these things.”

O’Neill also has to consider how much to rotate this squad. It’s a fine balance between keeping key players fresh, but also how much exposure to give his young squad.

Of the 26-man squad, 17 of the players are aged 25 or under and only three – Josh Magennis (36), Paddy McNair (31) and Dion Charles (30) – are over the age of 30.

Arsenal’s Ceadach O’Neill, Everton’s Braiden Graham and Kieran Morrison, who is on loan at Sheffield Wednesday from Liverpool, are the three teenagers in the squad.

“I don’t want to put too many young players on the pitch in a game like that where they’re untried and untested at that level,” O’Neill said.

“We want to bring the younger players in to give them the best chance to be able to do well and to build their confidence and to build their reputation. That’s the challenge for us.”