The Dublin-Mayo rivalry has had many staging posts and one of them dates back to Paul 'Pillar' Caffrey's time.
His Dublin side fell short against Mayo in a famous 2006 All-Ireland semi-final during his time in charge.
Arguably though it was the day that sparked the modern rivalry. 'Pillar' Caffrey joined Joe Molloy in studio to reminisce but also to touch on this weekend's semi-final.
"In my four years in charge of Dublin that was the toughest day at the office," he said of '06.
"Never mind the stuff that happened beforehand. That was showbiz."
He added jokingly, "I've no doubt a fella called D. Brady was in the middle of that."
Of course, what he's referring to is the Mayo players' decision to warm up in front of Hill 16.
Dublin Reaction
That sparked a reaction from Dublin's players as pictured below:
"I've no doubt that Micky Moran and the great John Morrison, my old buddy, they had no knowledge when the [Mayo] boys went over for a photograph, the shout came, 'Let's go to the Hill End,'" he continued.
"From our point-of-view, we'd been told that they'd gone down the Hill End. That was our designated end. They were out three minutes before us. Next thing, it was panic, 'Pillar, Pillar, Mayo are gone down our end'. 'There's nothing wrong with that,' I said."
As Pillar explained, he left it to the players to decide how to respond to Mayo's actions.
"At that stage the fire was in the eyes, the belly and they said, 'Pillar, we want to go down to the Hill,'" he said.
He also pointed out that Tyrone had also once done the same thing by going down to Hill 16 in an All-Ireland semi-final his brother had played in.
"But I was glad the players chose to go down on top of [the Mayo side]. Because if we had come out jogging up to the Canal End and then you turn around and don't play well, everyone says, 'What did you back down for before the game had even started?' And that then becomes an issue whereas for the players themselves, this was no issue."