There’s something iconic about the mix of red and blue.
Many is the rivalry that has been painted in these primary colours: Cork v Dublin, Liverpool v Everton and Munster v Leinster among them.
Hugo Keenan will add his own brushstrokes in Limerick today but there was a time when he would have favoured tomorrow’s meeting of Arsenal and Chelsea in London.
A fervent Chelsea fan, the Leinster full-back was soccer to the core growing up.
His uncle Keith Dignam played for Shamrock Rovers and UCD in the ‘80s and his cousin Mark Dignam has continued on that tradition with ‘College’ in the Airtricity League.
Keenan was schooled in Blackrock College but spent most of his teenage years playing as a central midfielder or centre-back with Mount Merrion Boys in the Premier and Major divisions of the Dublin District Schoolboy Leagues (DDSL).
That’s a decent standard of ball in the capital.
“Yeah, I played (football) up until I was about 17, just with Mount Merrion. In first, second and third year I was on the lower-ranked (rugby teams) in school.
"I wasn’t getting near the first team so I was always concentrating on football.
“It was only in fifth year, 16, 17, that I started focusing on rugby. You want to make the SCT team in Blackrock so I stopped playing football in my final year and just focused on that. That’s how it kicked off (in rugby) and how I made Leinster 19s.”
He hasn’t played football since but it’s a sacrifice that is paying off as he makes up for lost time in the oval code.
Now 23, he has made just 11 senior appearances but today’s will be the seventh of the season as Leinster prepare for life after Rob Kearney.
Jordan Larmour is in pole position to inherit Kearney’s jerseys with club and country but Keenan is a worthwhile investment in himself and one whose abilities have been honed by a spell with the national sevens side in recent years.
“It gave me great exposure at international level at a time when in here (with Leinster) I probably wouldn’t have gotten that many shots.
"It was about honing in on skills that I wanted to improve on. You get so many involvements on the ball; your passing, tackling, everything has to be on point with sevens because you can’t get away with it.
It was great for me.”
So has Kearney who has proven to be a useful mentor even as he has blocked Keenan’s path to the big time.
Then again, patience has been a virtue for a player whose ambitions in the 15 shirt were stymied by the likes of Joey Carbery and Jack Power at schools levels.
Keenan was the starting full-back last month when Leinster fielded a scratch side for the PRO14 trip to Glasgow and won.
Leo Cullen has waxed lyrical about that performance since then but Thomond Park is another step up the ladder again for an inexperienced Leinster collection.
It’s not a side without nous. Scott Fardy and Devin Toner will anchor everything from the second row and the likes of Ross Byrne, James Lowe and Andrew Porter offer enough big-game experience and class to present Munster problems in this traditional festive bash.
But this is a raw bunch when viewed in its totality. Keenan is one of nine players in the 23 who have yet to experience Thomond Park at senior level. Conor O’Brien.
Ed Byrne and Ciaran Frawley have banked just 71 minutes combined in Limerick at this level. Keenan simply won’t have known anything like this before.
The only comparable occasion he could muster when this was put to him was an U20 Six Nations game with Ireland over in Narbonne three years ago.
Not exactly a like-for-like comparison.
“It will be tough. The lads have been telling me that playing in Thomond is such a hard place to go. The crowd is always loud and hostile.
"I’m sure they’ll try and get into my head. I’ll just have to park that.
"It’s a game at the end of the day, just like any other.”