The Pittsburgh Steelers will play at Croke Park this autumn
Tickets went on sale at 12pm on Tuesday and there were hundreds of thousands of people in the queue within minutes.
Ahead of the sale getting under way, an online waiting room was opened at 11am, with users then “allocated a random place in the queue” at 12pm, according to the Ticketmaster website.
A notice at the top of the page reads: “We are currently experiencing a high volume of traffic. Please sit tight, you will be directed to the site as soon as possible.”
Many fans have been left frustrated by the length of the queue, with more than 600,000 people currently in the Ticketmaster queue and estimated wait times of “more than an hour”.
Fans from the US are expected to travel for the game, along with fans from European countries where the NFL is popular, including the UK and Germany.
In May, the Minnesota Vikings were confirmed as the Pittsburgh Steelers’ opponents, with kick-off set for 2.30pm on Sunday, September 28.
The Steelers first visited Croke Park in 1997 for a pre-season game against the Chicago Bears, with around 30,000 fans in attendance.
The Rooney family, who have owned the Steelers since the team was formed in 1933, have Irish roots traced back to Newry, Co Down. The team has marketing rights for Ireland as part of the NFL’s Global Markets Programme.
Prices for the game were confirmed last week, ranging from the lowest category in the Upper Davin Stand at €85 up to €295 for the most expensive option in the central Lower Hogan and Cusack Stands.
Though Croke Park normally has a maximum capacity of 82,300, a reduced capacity of around 76,000 spectators has been confirmed for the NFL game.
Hill 16 and the Nally Terrace, normally standing areas, will have seating for the game. Hill 16 tickets did not go on sale today and will be made available at a later date, giving fans another opportunity to secure tickets.
For those unable to see the game live, more details on fan zone-style activities around Dublin are expected to be revealed in the coming months.