Diego Simeone steels Atletico Madrid to slay 'the monster' in its own lair

A draw against Barça in the Nou Camp will complete the fairy-tale La Liga triumph of Madrid's poor relations

The Atletico Madrid squad during training yesterday as they prepare to face Barcelona (Getty Images)

With 3,330 minutes of the La Liga season gone, it all comes down to one game this evening at the Nou Camp. "You don't 'deserve' the league; you 'win' the league," the Atletico Madrid coach Diego Simeone and his captain Gabi have both said in the build-up to a game against Barcelona that promises to be the most dramatic final-day fixture in the competition's history.

The pair have done their best to keep everyone's eyes on the prize and on the need to keep on keeping on for just one more week of what has been an exhausting season.

Simeone has been teased for his "one game at a time" mantra, but the Argentine has stubbornly refused to get carried away, even as the evidence mounted that this was turning into by far and away the greatest season in the club's 111-year history.

Atleti are after all the team whose reputation for choking whenever they come close to success was second to none until Simeone took over as coach two and half seasons ago. He knows the importance of not falling back into old habits – they have played Barça five times so far this season and have yet to lose. If they repeat the trick today they will win their first La Liga title in 18 years.

Atletico are up against a club with its own flaws. The dark clouds of "worst-scenario" pessimism are never far from Barcelona and they gathered over the Nou Camp about a month ago as the club seemed to give up on the title.

They had begun the season with a 7-0 home win over Levante and for 23 weeks of the campaign led the race, but after exiting the Champions League at the quarter-final stage – against Atletico – they lost away to struggling Granada and supporters, players and directors appeared to resign themselves to the fact they were now out of contention. Even a 3-2 win against old rivals Real Madrid in the Bernabeu the following week could not lift the gloom.

Barça thought that Real would not drop points, but they did; they thought Atletico would not drop points, but they did. And now they are one home win away from lifting their 23rd league championship.

Their coach Gerardo Martino talked last week about how delighted he was to have been wrong to write off his team's chances. And he explained: "It's a 38-game season but we have the chance to play it like a one-off final and we're at home" – though admitted that Barça go into the game knowing two of the three possible outcomes favour their rivals.

Reinforcements have arrived just in time for the last stand – Gerard Pique is back after six weeks out with a cracked pelvis and will take his place alongside Javier Mascherano in the centre of defence. While Neymar who appeared to have already sidled off to the World Cup early has reappeared and should be, at the very least, named on the bench.

"They are not in the best conditions but we are not talking about them having to play six games; it's just 90 minutes," said Martino of his increased options.

Pique's return to the defence is especially timely. Diego Costa has hit 27 goals in the league for Atletico this season – though he has yet to score against Barcelona – and will be joined in attack by David Villa, who will be more determined than anyone to complete this most extraordinary of title-clinchers in the Nou Camp.

Despite helping Barça win the 2011 Champions League final at Wembley, scoring in the 3-1 win over Manchester United, Villa has endured a hard time of late. He was criticised for celebrating a goal in the Spanish Super Cup at the start of the season against Barça and jeered when substituted against his old team in the Champions League.

But if Costa and Villa can conjure a goal then most neutrals believe Barcelona's task becomes almost impossible as scoring will be particularly difficult. Barça face the meanest defence in the league, with Thibaut Courtois, who is almost certainly playing his last league game for the club before he returns to Chelsea next season, on course to win Spain's coveted Ricardo Zamora trophy for the goalkeeper who has conceded fewest goals. He won it last year, too.

It will be an evening of adioses. Costa could well be waving goodbye to the Spanish League he has occasionally offended but more often than not thrilled. Martino will clear his desk after the encounter to be replaced by former Barcelona player Luis Enrique, who resigned from Celta Vigo today.

For the home side Dani Alves is almost certainly playing his last match before he moves to Paris Saint-Germain in the summer and Pedro, Alexis and Alex Song could all also be signing off depending on incoming bids. What a way to go.

For Barcelona this will go down as the league title they never believed they could win. For Atletico it will be remembered as the league title Simeone always told them they could take.

"There are a lot of supporters from other smaller clubs watching us thinking: 'we want to be doing what they are doing'. We are fighting against two monsters with huge squads, great players and top managers," he said of the way they have muscled in on Barcelona's and Real Madrid's domination of the Spanish League – not since Valencia in 2004 has a team from outside the big two finished top of the pile.

Both sides today will invoke the spirit of former managers. Tito Vilanova won the league for Barcelona with 100 points last year. His death last month is still fresh in the minds of the players who he first coached when they were wide-eyed teenagers 10 years ago.

Luis Aragones won three league titles as a player and one as a coach with Atletico. No one represented the ballsy underdog image of the club better than the former Spain coach who died in February.

Any Barça triumph will be dedicated to "Tito", while Aragones' name will be sung on the streets of Madrid if Atletico are champions.

Barcelona have no plans for the traditional open-top bus ride – in part because they believe there is no better way to celebrate than in their own stadium immediately after it happens; but also because to plan a celebratory parade they would have needed to believe they could deliver the trophy in the first place, which they barely did.

For Barcelona to prevail one thing may well have to change: Lionel Messi has failed to score against Atletico in any of the two side's five meetings so far this season.

For Simeone, nothing needs to change – just the same old Atletico denying Barça time and space and taking at least a draw from the fixture.

They will only have 447 supporters in the Nou Camp but their thousands of fans back home will watch on giant screens in the centre of Madrid. And if the truth be known, the whole of Spanish football will be willing them on too – desperate for a changing of the guard, a shaking-up of the old hierarchy – and for such a super-hero season not to go cruelly unrewarded.