Barcelona players during a training session, on Friday. (Reuters)

Madrid: La Liga is set for one of its most thrilling finishes when Barcelona host leaders Atletico Madrid in a winner-takes-all showdown at the Nou Camp on the final day of the campaign on Saturday.

Only twice in the history of Spain’s top flight has the title been decided with a direct head-to-head clash on the last day and when the calendar was set last year few would have expected Atletico to be competing with vastly wealthier rivals Barca for the championship at this stage.

Real Madrid, the world’s richest club by income ahead of Barca, were in contention until last weekend when they were beaten at Celta Vigo but it is the capital’s second club, who have about a quarter of the resources of the big two, who are close to pulling off a remarkable achievement.

Atletico have not been in contention in La Liga since they last won in 1996, tasting relegation at the start of this century, but are now in with a chance of claiming an historic La Liga and European double.

Whatever the outcome of Saturday’s game, thoughts will immediately turn to the following week’s Champions League final against Real in Lisbon, when Atletico will be looking to win their first continental crown and deny their glamorous neighbours a record-extending 10th.

Barcelona were given a boost on Friday before the title showdown when forward Neymar and defenders Gerard Pique and Jordi Alba were given the all-clear by medical staff.

Neymar and Alba have been out since suffering injuries in the King’s Cup defeat by Real Madrid on April 16, while Pique has not played since the Champions League quarter final, first leg against Atletico on April 1.

There is some good news for Atletico Madrid as well. Their top scorer Diego Costa has shaken off a leg muscle strain and will be in the starting line-up on Saturday, coach Diego Simeone said on Friday.

The Brazil-born Spain forward, who has scored 27 goals in La Liga and eight in the Champions League this term, missed last Sunday’s 1-1 draw at home to Malaga but returns to try to help Atletico secure the point they need to clinch their first domestic league title in 18 years.

“He is fine,” Simeone, who was in the 1996 title-winning side, told a news conference. “He trained normally without any problems and he will play from the start,” added the Argentine.

After 37 matches in La Liga, Atletico are top on 89 points, with Barca on 86 and Real on 84. If Barca, chasing a fifth title in six years, beat Atletico on Saturday they will be champions, as they would have a better head-to-head record after the title rivals drew 0-0 at the Calderon in Madrid in January.

A draw would be enough for Atletico to become the first side other than Real and Barca to win La Liga since Valencia in 2004. The last time the title was decided with a head-to-head clash was in 1950-51, when Atletico pipped Sevilla. The only other occasion was five years earlier when Sevilla edged Barca.

Atletico and Barca have already played each other five times this season in a series of closely-fought encounters where the Catalan club had the lion’s share of possession but were mostly thwarted by a mean defence.

Barca edged Atletico to clinch the season-opening Spanish Super Cup, when Neymar’s goal in a 1-1 draw at the Calderon in the first leg was enough to secure victory after the pair played out a 0-0 stalemate the Nou Camp in the return.

After holding Barca at the Calderon in January in La Liga, Atletico clung on for a 1-1 draw at the Nou Camp in last month's Champions League quarter-final, first leg and then won 1-0 in the return in Madrid. The game at the Nou Camp will be only the third “winner takes all” match on the final day of the campaign in La Liga history and the first since 1951.