He spoke to Newstalk's Team 33 at the launch of eir Sports' European football coverage
As a Welshman, it's not in John Hartson's short-term interest to see Martin O'Neill having too much joy in the World Cup qualifiers given that Wales and Ireland go head-to-head in the same group.
But of course there is a huge appreciation and fondness for the Ireland manager from his former Celtic player.
Speaking to Newstalk's Team 33 at the launch of eir Sports' European football coverage for 2016-17 about some of the European nights he experienced at Celtic Park, Anfield and Highbury, Hartson recalled a particularly memorable O'Neill half-time team talk against Liverpool during a 2-0 victory in the 2002-2003 UEFA Cup quarter-finals in which the ex-Arsenal, West Ham and Coventry City target man scored this beauty:
"Basically Martin said, you've got this opportunity. It might not ever come again," said Hartson of the half-time team talk which preceded the goal.
"The way he went round the dressing room, every individual was given a specific talking to and the words certainly hit home and we went out in the second half and we were brilliant. And once I got that second goal, you can imagine the feeling."
He added that the team talk was "special and hit home for every single player. A lot of people to this day say that team talk was something out of the ordinary and Martin's capable of that."
As well as highlighting the Irish victories over Germany, Bosnia and Italy in the past twelve months, he also touched on the wider brilliance he feels O'Neill possesses.
"Martin O'Neill is incredible and I don't care whether you print this. Martin used to do that every week at Celtic. You've got to follow and understand the man. [Look] what he did at Leicester with two League Cups, what he did at Aston Villa. He finished sixth, they got relegated and they'd not been anywhere near it. Before he took over from David O'Leary, they were in the bottom three. So you (Ireland) have an exceptional manager and this is why when Wales play the Republic of Ireland - Wales are in a great moment at the minute - but even so I still think when they come up against Ireland, Martin will have a plan. His teams are very, very difficult to beat in general - we were difficult to beat at Celtic. We were strong, he made us all committed. He's doing the same with the Republic. Four or five years ago, you're telling me that Republic of Ireland would get a result in Serbia, 2-1 down? Maybe, Robbie Keane with the way he was, possibly. But that never-say-die attitude, his teams go to the very, very end and that's what Wales are up against."
In the chat which we will broadcast on Team 33 in the next couple of weeks, he also discusses European nights for Arsenal and Celtic as well as playing in front twos and his regret at not getting the chance to line out for hometown Swansea City even though a move nearly happened.
eir Sport will broadcast all six of Dundalk's Europa League group games on a free to view basis. The eir Sport pack is the only place to view the rest of the Europa League action including all of Manchester United's games as well as every Champions League game.