Questions on the alleged incident which prompted Keane to ask for Gardaí to be called to the team hotel in Portmarnock were understandably to the fore as O’Neill and skipper Robbie Keane spoke to the press this evening, but the message from the manager was unequivocal.

He said: “It’s only a distraction, that’s all it was. I made a statement earlier on today and there’s not really much more I can talk about.

“But I think we are fine, I think the players are fine, I think the man in question is fine too and we are ready to go.”

Quizzed further about his number two, O’Neill replied: “He’s okay – he’s actually here with us now, so if we could end the press conference right now it would be great because you will catch him.”

The manager was briefly nonplussed when asked if the former Ireland captain had addressed the squad on the matter, and moved swiftly on.

He said: “Why would he do that? No, no, he spoke to me. I don’t think Robbie as captain was particularly interested in hearing what had happened at that time - I don’t think so, anyway.

“Listen, the incident is over at the moment and I think that’s it. You mentioned it being a distraction, and that’s really it.”

If events in Dublin had dominated the pre-match agenda outside the Republic camp, there is little danger of it doing so as the countdown to an eagerly-anticipated qualifier nears its conclusion.

O’Neill was more concerned about the loss of central midfielders Glenn Whelan and one of the men fuelling the other major talking point this week, James McCarthy, to injury.

Whelan was always an outsider after breaking a bone in his leg during the 1-1 draw in Germany last month, but there was better news about Glasgow-born McCarthy – who had been promised a hostile welcome – as scans confirmed no significant damage to his hamstring.

O’Neill said: “James, I suppose, realistically was always an outside chance. He has improved immensely since Sunday – in fact, he went for another scan and the scan is actually quite clear, so that is really good news for the lad.

“But really I suppose since it is a muscle injury, then it was a concern for us that he needed to probably do something today and see what sort of reaction he had.”

Darron Gibson and Jeff Hendrick are seemingly the main candidates to plug the sizeable gap left in the heart of O’Neill’s team, although he has also handed a key role to Stephen Quinn in the recent past.

But whichever 11 men eventually run out ahead of kick-off, they will be sent on their way by a manager determined to emerge with a positive result at a stadium where he did that more often than not during his five years as Celtic boss.

O’Neill’s side claimed three league titles, three Scottish Cups and one League Cup, as well as reaching the UEFA Cup final, during his tenure to establish himself firmly in the affections of the locals.

However, he is determined to send those same fans home this time wearing frowns rather than smiles.

O’Neill said: “I must admit, it will be really strange to walk into the club and walk right to the away dressing room rather than left.

“I said jokingly – and I think I actually mean this – I’m not even sure that I ever set foot in the away team dressing room, ever. It will be strange, I must admit. Just after this press conference, I fancy a little walk around.”

The Irish arrived in Glasgow sitting joint top of the group alongside Poland, with both sides having claimed seven of the first points available to them, three ahead of both the Scots and world champions Germany.

Victory at Celtic Park would provide a massive boost to their hopes of making it to France, while a draw would be more than useful, although O’Neill insists it is not a must-win game.

He said: “When we finish tomorrow night, we will have have played three pretty difficult away games and will still be in the hunt regardless, so what we do in the Aviva Stadium in 2015 will probably determine everything.

“But of course, it’s still a very, very, very significant match tomorrow night.”