President Michael D Higgins is to be presented with an Irish jersey when he attends the Croatia match tonight.
The President, a lifelong Galway United fan, will be in Poznan for two days as the 25,000 strong Green Army exodus hits town.
Mr Higgins will be presented with the replica top by manager Giovanni Trapattoni in the Stadion Miejski in a private function as 44,000 fans arrive.
Local officials estimate there will even bigger numbers in the city by the time the whistle blows against Croatia thisd evening.
The Department of Foreign Affairs said they have had no serious incidents to deal with in the build up to the tournament this week and fans were in good spirits.
Minor scuffles involving Polish fans broke out in the main square on Friday night after the competition opener between the hosts and Greece. Riot police and mounted units swiftly intervened.
Several Polish fans were taken away in police vans. No Irish were involved.
Six months and a day since the draw was made, one group of Irish fans celebrated their arrival in Poznan for the opener yesterday.
Richie Barber from Perrystown in Dublin left Dublin in a campervan on Tuesday night on a ferry to Holyhead.
“We drove to Hull. Got the party boat to Rottterdam and drove to Berlin and then Poznan,” he said. “There’s 11 of us altogether. We’ve an apartment, four couches between us to sleep on.
“As the draw was being made, the apartment was being booked and the tickets were being sourced.”
A special campervan zone has been built to accommodate the Irish with space for 300 motorhomes and 500 tents.
PA