Paris - Chris Coleman said it would be dangerous for Wales to look beyond Saturday's last-16 clash with Northern Ireland, despite the open nature of their half of the Euro 2016 draw.
With title-holders Spain, world champions Germany and hosts France on a collision course with each other, the stage is set for an outsider to potentially clinch a place in the July 10 final.
But Coleman, whose side finished top of Group B above England, insisted the only thing on his players' minds was this weekend's game at the Parc des Princes in Paris.
"We can't afford to look past the next game, nor can Northern Ireland. It's all or nothing this game," Coleman said a press conference on Friday.
"We have a lot of confidence from our last performance which was outstanding, but our focus is on tomorrow and we can't talk about anything else.
"The next (game) is always the biggest one. Both teams find themselves in a position where they've earned respect and attention.
"It'll be who can handle the spotlight best and who's capable of performing under the tension and pressure.
"That pressure is one we've been screaming for years that we want, so there are no complaints now that we're here."
Should Wales advance to the quarter-finals they could face either second-ranked Belgium - a team Coleman's side took four points from during qualifiers - or Hungary.
But when asked whether the Welsh could draw impetus from Leicester City's improbable Premier League title success, Coleman said such thoughts would simply expedite their return home.
"Such is the quality of company we're in at this tournament, if we ever dared to think the next game is a stepping stone to something, it's all gone, we're done, we'll be on the next plane home," he said.
"There's not a team in this tournament that can think like that, not Spain, not Germany... nine times out of 10 you look at games that are very, very close such is the quality that's here.
"We can't look past the next game. I wouldn't dare do that, the players wouldn't. We can't look past the next 45 minutes, it's a huge challenge tomorrow for both teams."
Coleman also called for cool heads as they face another of the home nations after admitting Wales succumbed to their emotions during a heartbreaking 2-1 defeat to England in Lens in the group stage.
"We got caught up in a game with the emotion of it, because it's a derby game. That's what we needed to put right against Russia which we did.
"Tomorrow, the 90 minutes doesn't last forever, it comes and it goes and it's up to us how we want to enjoy that experience.
"Take the emotion out of it. Don't get me wrong, you need some emotion but if you have too much of it your gameplan's out the window."