Martin O'Neill has admitted telling some of his Republic of Ireland players they will not be going to the Euro 2016 finals will be one of the hardest parts of his job to date.

The 64-year-old will spend the next few days agonising over how to reduce the 35-man party he named initially down to the 23 he will take to France with only a handful of training sessions and warm-up games against the Netherlands and Belarus on which to base his decisions.

O’Neill knows the task will be significantly more difficult than during his days as a club manager and is acutely aware there will be heartbreak for some.

He said: “At club level, it’s a pretty frequent event. On a Friday, you’re telling a group of players, ‘You’re not going to be involved, but there’s a possibility of being involved the next week’.

“Because you are dealing with players, if you have on a Friday left them at the train station because they are not heading down to the game, you will see them again on a Monday regardless of the mood.

“But these players here at international level give up their time and energy, want to be involved and have been involved – and it certainly wouldn’t be for the money, it’s really for the glory.

“So yes, there are a few decisions to make and there will be disappointment, and it certainly wouldn’t be easy for that reason, because these are international players who want to play for their country.”

Asked how he will tell those players who miss out that they will not be on the plane, O’Neill said with a flicker of a smile: “If there are one or two who are bigger than me, I may well write to them.”

It will be O’Neill’s first major tournament finals as a manager, but he did experience the 1982 World Cup finals as a player with Northern Ireland.

He knows it will be very different this time around, but is confident he will be able to call upon his memories of that trip as he plots the way forward for his current charges.

He said: “Naturally, it was a great competition for us, but it was so long ago. I was nearly going to say I forget about it, but I don’t. I probably think about it every night – that’s not true.

"Billy Bingham at the time gave me the captaincy of the side during the lead-up to qualification, and I thought it was a great, great honour and you felt a certain responsibility for the players, how they looked after themselves during the course of the competition, and naturally how you played.

“But the ultimate responsibility, I suppose, falls on the manager and that is something that will be a bit different to being the captain of the team. I am looking forward to it immensely.”

In the shorter term, O’Neill is looking for players who are not yet certain of their places in the squad to stake a claim against the Dutch in Dublin on Friday evening and Belarus in Cork four days later.

He said: “Really, it is these training sessions and the matches that ultimately will make my mind up on things.”

Midfielder James McCarthy and central defender Ciaran Clark may not play against the Netherlands as they continue to nurse thigh and ankle problems respectively, although O'Neill is not unduly concerned over either.