Dublin is facing the prospect of a logistical headache with two big sporting fixtures on either side of the Liffey potentially colliding on the same afternoon later this month.
The NFL Division 1 and Division 2 finals have been set in stone for Croke Park on Sunday, April 28 since the fixtures were made last October.
But earlier this week the ERC made the draws for the Heineken Cup semi-finals and it was decided that the Aviva Stadium would host a semi-final on that date if Ulster are involved.
Ulster must first beat Saracens in their quarter-final clash for that scenario to arise. But any football league final involving Dublin would have the capacity to edge a Croke Park attendance figure well above 40,000.
The potential crowd would not be impacted on for either fixture but if it does transpire it would provide quite a logistical and security challenge for the city.
The GAA and IRFU/ERC have generally managed to avoid clashes of this magnitude between Croke Park and Aviva Stadium/Lansdowne Road in the past.
In 2006, the football league finals clashed with the Heineken Cup semi-final between Munster and Leinster but the Division 1 final between Kerry and Galway was played in Limerick on the Sunday evening with the Division 2 final between Donegal and Louth taking place in Cavan.
The Division 1 league semi-final placings won't be determined until Sunday evening when the final round concludes but Dublin, Kildare and Tyrone are already qualified.
A Dublin/Kildare or Dublin/Tyrone final would have the potential to draw the biggest crowds to Croke Park with Westmeath, who are already qualified, and Derry the most likely Division 2 final pairing.
The GAA's Central Competitions Control Committee will finalise venues for the league semi-finals on Monday with Croke Park the probable venue because of the teams involved.