One Ulsterman will be swapping the green and white for Spain's red and yellow tonight.
Thousands of Northern Ireland fans will be keeping their fingers crossed that David Healy will lead his team to victory over the Spanish.
But John Mulhern, general manager at La Tasca restaurant in Belfast, said he will be donning the colours of Spain instead.
"I'll be supporting Spain," he admitted.
"I've worked here so long, about three and a half years.
"I think if I didn't support Spain I think I would be lynched!"
"We will be putting on the Spanish tops and go to one of the bars here at the Odyssey to watch the game."
His Spanish co-worker Joaquin Gomez (34), who has lived in Northern Ireland for about four years, said he is confident of a win.
"We are confident because we have qualified anyway," he said. " I think we are going to win, to be honest.
"We aren't risking much, but I suppose maybe we will be relaxed a bit and we could possibly take our minds off the game a bit."
"And I hear that the Spanish team that will play is not their first team."
Mr Gomez added: "There will be at least four of us supporting Spain. I don't mind if we are outnumbered, just as long as we win! It should be a good atmosphere."
Meanwhile, pubs across Belfast are preparing for hundreds of fans to gather to watch the game.
One of the popular spots is the Botanic Inn on the Malone Road.
Member of staff Ann Duffy said they are prepared for hundreds of fans-both Northern Ireland and Spanish.
"We are expecting fans from about 5.30pm but it will be crazy from 7.30pm. It is a big game.
"Everybody will be getting into the spirit of the match.
"But it won't just be Northern Ireland fans, the Spanish will be here too.
"There should be a great crowd and great craic."