The men in possession of the Millennium Stadium corner flag are David Harris, Rob Fallon, Glenn Dalton and Rory Carton, who secured the memento at the match last week thanks to the assistance of a female steward.
They appeared on last Friday's 'Late Late Show' to tell their story and plug the auction.
The auction, which currently has a reserve bid of €1,000 from Mary Mac's Pub in Ballsbridge, closes next Monday (April 6).
All proceeds arising from this sale will be donated to the Children's Medical & Research Foundation at Our Lady's Children's Hospital in Crumlin, Dublin.
The Foundation is the fundraising umbrella for both the Hospital and the Research Centre.