With four of his players in the starting XV and another four on the bench, there is a distinct amount of vested interest in the match for the former NSW Waratahs assistant coach, who lists 'Uncle Bob' Dwyer among his old Randwick buddies, and admits to have been a fly-half with the famous Sydney outfit, "three or four stones ago."
But with the day job of provincial matters on the backburner this week - despite Munster's impending Heineken Cup quarter-final showdown with English champions Leicester Tigers - Gaffney is in the thick of Ireland's rugby mania as the Grand Slam decider looms - and one battle in particular stands out.
"Both sides have been good in the set piece so far this season," he says, speaking from his Limerick base after a morning's training. "But for me one of the most enticing contests is going to be at the breakdown, which basically means Neil Back v Keith Gleeson."
Gleeson, the 27-year-old former Australian Barbarian, helped himself to a pair of tries in Ireland's nailbiting 25-24 win over Wales in Cardiff last Saturday, and is a player Gaffney knows well, having coached him for two years while assistant to Matt Williams in the Leinster set-up.
"Gleeso has the edge over Back in terms of size, but Back has other attributes that he can bring to the game as well. For me that is the battle to watch, and with all the other plots in the game, it will be a contest in itself."
With media and public expectations reaching unprecedented levels - for those under 60 years old anyway - Gaffney sums up the effect, or lack of, that it may have on the players who are led by another of his old Leinster contingent, the ever-reliable Brian O'Driscoll.
"It's a huge thing for the Irish, you have to understand that," he says. "They haven't won the Grand Slam for 50-odd years. The tension is building here, and they're sitting on the doorstep of greatness.
"Sure, you might think that the media pressure would add to it a bit, but the national team boys have been around for a while now and they're used to it. They'll steer away from reading and watching too much of it, and they put enough pressure on themselves to be going on with. They have to focus on their job.
"I may send one or two of the Munster boys a quick text message on Friday or something to wish them luck, but I've purposely not been contacting them, because when they're with the national squad they're under the charge of Eddie O'Sullivan and his team."
And the captaincy of Brian O'Driscoll, who despite raised eye-brows on his appointment during Keith Wood's injured spell is still to be defeated as Irish skipper?
"Brian might come across as a quiet lad, and I guess he is, but a captain doesn't have to be a shouter and a bawler. A captain has to do the toss and make some reasonably hard decisions on the field.
"Ireland are lucky in that, like us at Munster, they have a solid base of senior professionals who can help Brian and communicate with the players during the game, people like your Anthony Foleys," he says of the Munster No.8, who has assumed an increasingly vital role within the pack. "People might have thought it an odd decision to make Brian captain, but I didn't at all, and he has the right people around him to remove a bit of the burden."
Having been in the midst of top-level rugby in Ireland for more than three years now, has Gaffney seen a major shift in standards or philosophy with the national team?
"They've improved alright," is the immediate verdict, calmed somewhat by a slight history lesson. "But let's not forget that they almost won the Grand Slam in 2001 as well.
"They suffered a shock defeat to Scotland at Murrayfield in the year that it was delayed because of foot-and-mouth, and they beat England and France that year. I'm not saying that they would have won the Grand Slam had it not been for the delay, but it just shows you that they were still up there, and it hasn't been a surprise to me the way they have played this season. The difference between now and some Irish teams of the past though, is that they can now string 10 or so games together before they get beaten."
One point of much debate throughout the country is just who should wear the No.10 shirt, with Gaffney's Munster icon Ronan O'Gara having seemingly started the year as the first choice, but finding himself injured in the Celtic League Final.
Ulster's David Humphreys again seized his chance with both hands to start every game so far, and got the vote again for Sunday's colossal match, despite O'Gara's heroic injury-time drop-goal to win last week's nail-biter against Wales.
"I work with ROG [O'Gara] every day, and I'm very disappointed for him, especially after the way in which he got injured," says Gaffney, referring to the Celtic League showpiece in Cardiff where O'Gara was stretchered off after having his leg stamped on by Neath's Brett Sinkinson, an action which earned the Wales flanker a hefty ban.
"I have a hell of a lot of time for Ronan, and he and David Humphreys are both different players. It's a selection process though, and I wouldn't want to start criticising the national team's selection, because it is their job to pick the team and not mine. I'd love to see ROG introduced at some point on Sunday from the bench, and I'm sure he will be.
"Everyone is going on about his drop-goal against the Welsh last Saturday, and it was one of those moments that will go down in rugby folklore. It was great to see him there, and I just think back to his unlucky injury in that Neath match.
"I almost actually missed the end of the Wales game on Saturday because due to some typical piece of scheduling I was stuck on an aeroplane with the Ireland Under-21 squad when the match was on. I saw a few seconds of the match on the TV at the airport, and then sped back to watch the last 20 minutes or so on the telly. What can you say about a finish like that?"
So what about Sunday's upcoming festivities?
"Well, I really hope I have a hangover on Monday," jokes Gaffney. "But seriously, England are very good right across the paddock, and looking at it you'd say that the English go into it as favourites - and rightly so.
"Their scrum and line-out is superb, but then again the Irish line-out is. I had heard our scrum was a little wobbly against the Welsh, but as I said I never saw enough of the game to make a proper judgement of it. England probably won't scrum as aggressively as the Welsh did, so we'll have to wait and see.
"The Irish are very good generally in the set piece though, as they proved against Australia in November. They have great competitors like Gary Longwell and Victor Costello, and if we win the set piece we're in with a chance. I'll be there myself with the Munster contingent, and it should be a great day for all the Irish fans.
And the verdict?
"I know you're bound to think I'd say this anyway, but in all honesty I'm very confident of an Ireland win. The players have a lot of belief in it, and so do I."
Come Sunday at Lansdowne Road, eager fans across the rugby world will know the winner for themselves.
Courtesy of Planet Rugby.