On June 8, 1990 the eyes of the world were on Milan's San Siro as reigning champions Argentina kicked off the World Cup against a Cameroon side that had been written off as no-hopers before the draw had even been made.

Fans in the stadium and around the world saw Diego Maradona's side fall to one of the greatest upsets in the tournament's history as Francois Omam-Biyik headed in the only goal of the game to give Cameroon a 1-0 win.

For Scotland fans though, the tournament wouldn't really begin for another three days. Having qualified every four years since 1974, the nation's hope was that this time we would go further than the group stage.

That would mean performing against Brazil and Sweden but before that there was the small matter of dealing with the bottom seeds in the group.

Costa Rica had reached the finals for the first time and little was anticipated from the Central American side. With Mexico banned from qualification, Los Ticos had finished as top of the CONCACAF table but arrived in Italy in hope rather than expectation.

There were no FIFA rankings at the time to give everyone a shorthand for the supposed difference in quality between the sides (though the Elo ratings show Scotland as 29th ranked team and Costa Rica as 49th going into the game). However, in the build-up it was clear from both sides where the balance of power was and what the expected outcome would be.

Scotland captain Roy Aitken highlighted the Cameroon result as an example of what could happen but was still more than confident his team could deal with a "lesser" nation.

"Preparation is out the way now and it's all down to the nitty-gritty stuff," he told STV. "The game tonight is one we're all looking forward to.

"Obviously [the fans] are going to be confident because Costa Rica is one of the so-called lesser nations in the competition, although we all got a surprise last week when Cameroon beat Argentina and it shows that nobody can be taken for granted.

"We'll be treating Costa Rica with the utmost respect, the same way as we would a game against Brazil or Sweden.

"As far as the fans are concerned, they can be sure that the team will give them 100%. We know what's at stake and we know what we have to do to win the game.

"And we know that if we play to our capabilities then we'll win the game comfortably."

Scotland manager Andy Roxburgh shared Aitken's view and, when asked if he was confident, said the focus had to be on his team.

"It's more important how confident they are," he said, pointing to the players training behind him. "They're the ones who have to go onto the pitch and perform for us.

"I've always been confident that our lads are capable but we have to produce the goods and I think the team from Cameroon showed everyone what can happen. I think we have to be wary of that and we have to be at our best to win."

Asked if the biggest threat to our chances of progression was ourselves, Roxburgh dismissed the idea as a problem with our national psyche.

"That would apply to any team," he said."If any team falls below par then they're in danger of losing a match.

"It doesn't just apply to us. We have this typical, parochial attitude that it's only us.

"I'm sure that people in Argentina will be saying that they were below par and that's why they lost. So you have to be at your best in a World Cup tournament , particularly in the finals like this.

"It's important that our lads perform to their maximum.

"We have to give all of our opponents respect. We know what they can do. They have some strengths in their team and they obviously have some weaknesses as well. That applies to everybody and we have to make sure that our attitude, more than anything, is right in this match."

STV also interviewed one of the Costa Rican players. Juan Cayasso, a 28-year old midfielder who played his club football with Deportivo Saprissa looked nervous but believed his side had more than a chance.

"The team is getting better day by day," he said. "So we're waiting just for Scotland. It's a difficult team, a hard team.

"We have to work hard because they want to win this. We're just going to do what we know and try to finish with a good result.

"We have faith that we can beat them."

It wasn't the last we would hear of Cayasso.

Around 12,000 Scotland fans cheered the side on in the Stadio Luigi Ferraris but the World Cup party didn't go the way the Tartan Army expected.

Brian Glanville's Story of the World Cup describes the action in straightforward terms.

He wrote "The Scots couldn't exploit Costa Rica's indifferent prowess in the air, all their pressure producing only a handful of chances. Conjo, the accomplished Copsta Rican goalkeeper, made a couple of good saves, Cayasso scored the only goal.

"It came four minutes after the interval. A diagonal run by Marena, a backheel by Jara, and Cayasso had scored.

"Scotland were in trouble again."

The backlash was inevitable and fierce with Roxburgh and his players in the firing line.

Having been calm in his immediate post-match interviews, Roxburgh became tetchy when addressing the media later and being asked if he had a message for the fans after a result that would go down as one of the low points in the team's history.

"[The fans] will be, I'm sure, as disappointed as we and the players are," he said.

"We are all Scots, the players, the management and the supporters and if things don't work out the way we want them to work out then all of us are bitterly disappointed.

"Today was the classic example of the team who defends and counter-attacks, they get their breakaway goal and their goalkeeper has a wonder display.

"I saw the same goalkeeper at Wales recently and he looked really, really dodgy.

"Today he had a wonder display and it's the classic example of the small team getting the result when the other team has given all the pressure."

STV spoke to one of the Scotland defenders after the match and he was already looking ahead to the challenge of Sweden and Brazil. Alex McLeish knew the Scots would find it tough to qualify but he suggested Costa Rica had been lucky and it might be their only success in Italy.

"If ever there was an uphill struggle then it's the next two games," he said. "It's two really good sides we're playing against and incidentally, I think they'll beat Costa Rica comfortably.

"The Costa Rica goalkeeper was brilliant today and I don't think he can play that well again."

Scotland went on to beat Sweden 2-1 and keep their hopes alive going into the final group game but a goal from Brazil's Muller nine minutes from time ended the dream.

Costa Rica proved McLeish wrong. They also went down 1-0 to Brazil but a 2-1 win over the Swedes saw them reach the knockout stages at the first time of asking. They were pitted against Czechoslovakia in the round of 16 and a 4-1 defeat ended their journey.

Since, they've qualified for three more finals, reaching the quarter finals in 2014 and aiming for a repeat this year.

For Scotland, Euro 96 and France 98 followed but we've been in the international wilderness since. McLeish has been tasked with ending that exile and his journey begins with a reminder of a game he, and most Scots, wish they could wipe from their memory.