Pals playing name game as historic day of reckoning awaits
They are very much their own men but share the same surname, the same country of birth, the same career path and this week they shared a prestigious managerial award.
Tonight in Paris they will share the same desire for a favourable draw in the Euro 2016 finals - one that gives them every chance of making it to the knockout stages.
Before the qualifying campaign for the tournament began Michael O'Neill and his Northern Ireland team were written off in some quarters as no-hopers.
Martin O'Neill's Republic of Ireland side dealt with similar suggestions during an unconvincing spell in their group phase.
But both came through, in contrasting ways, to reach the finals and are now excited to see who they will end up playing in France next year.
Northern Ireland topped their group ahead of Romania and Hungary to qualify in some style while the Republic, having finished third in their group behind Germany and Poland, were forced to journey a little longer, via a play-off victory over Bosnia, to reach their preferred destination.
The O'Neills, who are good friends, chatted in Dublin on Wednesday about the various possibilities of tonight's draw when they were declared joint winners of the 2015 Philips Manager of the Year award.
Tonight in the Palais des Congrès de la Porte Maillot in the French capital, if they get a chance in between all the media demands, the pair may share a glass of wine and discuss who fared better.
What they know already is the earliest they could face each other is in the knockout matches.
When the Republic qualified a month after Northern Ireland had done it, the younger O'Neill sent a congratulatory text to his more mature pal joking that they they would see each other in the semi-finals!
Both nations are in Pot Four in terms of the seedings, as are Wales.
England, though, are in Pot One so there is a chance that Michael or Martin could take on Roy Hodgson, Wayne Rooney, Joe Hart & Co.
It is intriguing to note that while the 63-year-old Republic boss would be content to draw the English, the 46-year-old Northern Ireland manager would prefer to avoid that clash early in the competition and all the hype that would go with it.
The former Shamrock Rovers supremo said: "For me, the big thing is that an England game overshadows everything. Everyone will focus on 'you're playing England, you're playing England'.
"There's three games in the group and you have to find a way of getting four points to get out of the group. Four will give you a good chance, three might be well be enough and I think England could possibly be detrimental to that. If it comes, though we'll deal with it."
The former Celtic boss agreed that his namesake had a point, but in reference to possibly being paired with England added: "I genuinely don't have a problem with it. I'm going with the feeling, okay, alright, whatever will be, will be. That's how I feel."
O'Neill puts his relaxed state of mind down to coming through a qualifying group that contained world champions Germany, Poland, Scotland and Georgia.
You get the feeling he thinks after handling that, he'll take whatever is thrown his way tonight.
Apart from England, the other Pot One teams are Euro holders Spain, Germany, Portugal, Belgium and France.
The Northern Ireland boss would relish meeting the hosts for what he says would be 'a special game' but admits if his ambitions of reaching the knockout stages are to be realised avoiding Italy, the top team in Pot Two, would be a major help.
He did add, though, that no matter the opposition, his players, led by inspirational skipper Steven Davis (pictured), have already shown they can mix it with the big boys.
"In my time as manager we have shown how capable we can be against big nations like Portugal and Russia. Those are games we'll reflect on when we go to the finals," he said.
"The games that have disappointed were the ones against the weaker nations where we left ourselves down."
O'Neill, who burst on to the Irish League scene as a goalcoring teenager at Coleraine to earn a move to Newcastle, adds that the fact the Euro 2016 games will be the biggest in the lives of his players can work to their advantage against opposition used to, and perhaps fatigued by, playing this level of fixture on a more regular basis.
He said: "Lots of the players our boys will come up against are challenging for leagues, Cups and the Champions League. So when it comes to the tournaments, I can understand that there's an element of fatigue and mental fatigue for them.
"Our players are going into their first tournament in 30 years. They're cock-a-hoop to be going. We don't have any players in the Champions League.
"That can work in our favour to some extent.
"The biggest thing that will gives us a chance is our preparation by ensuring that is right.
"That's my job and I'll make sure we do it right."
To that end O'Neill, the first manager to take Northern Ireland to a Euro finals, will stay on in France after the draw to assess base camps for next year with Perpignan the current favourite.
The other O'Neill and the Republic of Ireland will also finalise their base after tonight's draw.
The former Leicester, Aston Villa and Sunderland manager has been at recent major tournaments as a television pundit, but his only experience of competing in one dates all the way back to 1982 when he was captain of the famous Northern Ireland team who reached the second phase of the World Cup, defeating hosts Spain en route.
It was interesting this week hearing O'Neill recall that competition from over 30 years ago and relate it to Euro 2016.
"I try to think back to 1982 with Northern Ireland," said the man who won the European Cup with Nottingham Forest having joined the Midlands outfit from Distillery.
"We were based in Valencia but we had only one game in Valencia. They felt that the hotel was good, which it was, and the facilities not too far away weren't too bad.
"But on the morning of the games we had to travel by plane, to Zaragoza for the two matches we had there, and it was a really hot summer.
"Nowadays I think you have to be ensconced in the area 24 hours before the game so that makes a difference.
"I think, if your base is not a million miles from an airport you will be okay, but of course, with security and such things there might be added pressure, so let's see how the draw works out and where we are."
The last time the Republic qualified for the Euro finals in 2012 - losing all three group games - there were suggestions that cabin fever set in because then boss Giovanni Trapattoni had taken the squad away for too long prior to the tournament.
One suspects it will be different with O'Neill in charge.
"Players nowadays don't like to be away too long," he said.
"They are never a million miles away from an app or a mobile phone, as none of us are but we will see."
On qualifying for the knockout stages O'Neill wants his team to have no regrets. "We have everything to play for. Let's go for it, just really let's go for it," he says.
Northern Ireland manager Michael O'Neill will be thinking the same.