It was the decision that angered a nation. Just months before his home country hosted their first World Cup for 64 years, one of their own had, they felt, committed an act of footballing treason. Diego Costa had turned his back on Brazil, and he had taken allegiance with the Spanish.
Born in Lagarto on Brazil's east coast, and beginning his footballing education in Sao Paulo, there seemed little doubt when Costa began his impressive goalscoring run at Atletico Madrid that this was a future Brazil international. Such predictions were proved correct when on 21st March he made his Selecao debut against Italy in Geneva, his second cap coming just days later against Russia in London.
Just six months on, and Costa had already made the decision to transfer nationality. Left out of Brazil's squad for the Confederations Cup, the striker made his feelings public. "I looked at everything and saw that it was best to play for Spain," Costa said. "That is where I have done everything. All that I have in my life was given to me by this country."
In September, the Spanish federation made things official, a statement on its website reading that "the player [Costa] communicates in a letter to Julio Cesar Avellada, secretary general of the Brazilian football federation (CBF), his wish to be available for the Spanish national team."
Predictably, the reaction from the Brazilian camp was one of anger. The president of the CBF promised to use "every legal means possible" to prevent Costa representing Spain, whilst the Selecao's manager, Luiz Felipe Scolari, offered a far more emotive response, as he said: "A Brazilian player who refuses to wear the shirt of the Brazilian national side and take part in the World Cup in his own country must automatically be uninvited. He is turning his back on the dream of millions."
It is important to note that Costa should feel no real guilt for his decision. Article 7 of the Regulations Governing the Applications of Statutes, FIFA Statutes, states that a player who plays for a continuous period of more than five years after reaching the age of 18 in the territory of the relevant national association, can play for that national association in international football providing that they have not played an official competition match for another national state. Costa had played only in non-competitive matches for Brazil, and therefore was ripe for picking by Spain. Surely the Brazilian authorities knew this? Would it not have made sense to pick Costa for the Confederations Cup, thus ending all doubt?
Major threat: Costa would have been an ideal fit for the Brazil team
Furthermore, Costa's nationality transfer is not particularly unusual. In total, more than 70 Brazil-born players have changed nationality to countries including Azerbaijan, Bolivia, Equatorial Guinea, Germany, Japan, Lebanon, Qatar, Togo and Vietnam, with Eduardo (Croatia), Marcos Senna (Spain), Deco and Pepe (Portugal) all high-profile examples of such an occurrence. Sebastien Bassong (France to Cameroon), Tomasz Radzinski (Poland to Canada), Kevin-Prince Boateng (Germany to Ghana) and Aiden McGeady (Scotland to Ireland) are familiar Premier League names who have chosen to switch allegiance.
That Diego Costa's change has been so high-profile owes much to the form of one European football's most dangerous forwards, and caps off a fairly remarkable ascent. Less than two years ago, this was a player who had never reached 10 goals in a league season during spells with Penafiel and Braga in Portugal and Celta, Albacete, Valladolid, Rayo Vallecano and Atletico in Spain. Even in late-January last year, Costa had scored just two goals in 14 La Liga appearances that season, the third goal in a 4-2 victory at nine-man Real Betis and the 'other' goal in a 6-0 romp over Deportivo in which Radamel Falcao scored five. Eight goals in 15 games followed until the end of the season, but there was still little sign that Costa's career was about to take off in such spectacular fashion.
Whilst Falcao's departure for Monaco last summer may have been seen as a disaster by many Atleti fans, the space vacated has instead allowed Costa to truly thrive. Given the responsibility of leading the line, with new recruit David Villa playing a supporting role, Costa almost immediately set about replacing the Colombian's goals at the Vicente Calderon, scoring 27 La Liga goals in 35 games as Los Rojiblancos won the league and reached the Champions League final. "He's such a good player. That's why we play the way that he needs," was the straightforward verdict of club captain Gabi.
Whilst it is the striker's strength both on the ball and in the air that gains the most plaudits, and leaves him on the brink of a move to Chelsea, that does a disservice to his skill with ball at feet - this is an all-action forward capable of using poise and precision in equal measures to power.
Moreover, Costa relishes physicality. Never far from controversy, the striker was sent off in the Europa Legaue last season for a head-butt on Viktoria Plzen's David Limbersky, and was caught on camera doing the same to Sergio Ramos during the Madrid derby. While at Vallecano, coach Jose Ramon Sandoval remarked: "You are the most consistent player I've had - you go into every game wanting to score and get a yellow card."
Hulk: Unconvincing for Brazil
This is a forward who until this season had received more cards in La Liga than had scored goals. However, such a temperament owes much to Costa's passion, determination and desire - these are assets that simply make him an easy player for fans to admire.
Costa owes much of his passion to his football upbringing on the streets of Lagarto. "On the pitch I fought with everyone," he said. "I couldn't control myself. I insulted everyone, I had no respect for the opposition, I thought I had to kill them. Boys who grew up playing in academies are taught to control themselves and respect others, but no one ever told me otherwise."
Unfortunately for Brazil, this is exactly this style of forward they are lacking, only serving to heighten the disappointment felt back home and the resentment that Costa will surely experience this summer as Spain prepare to kick-off their defence of the World Cup against the opponents they beat in 2010's final, The Netherlands, in Salvador on Friday. While Neymar is the pin-up boy, the Selecao lack that obvious focal point of attack around which the Barcelona forward can be so effective.
Hulk is perhaps the obvious choice, but public opinion in Brazil appears fairly damning against the Zenit St Petersburg forward. Fred and former Manchester City failure Jo are the other two primary options for the role, but neither are considered as worthy candidates to lead Brazil to World Cup glory. The conclusion becomes increasingly evident - Diego Costa fits the bill perfectly, and would likely have been an automatic starter this summer.
Brazil's loss is Spain's notable gain. While the World Cup and European Championship holders have options aplenty behind the striker, they, too, have space in their squad for a multi-faceted forward such as Costa.
If all goes to plan for both countries and their groups are won, Brazil and Spain could meet in the final in the Maracana on 13th July, and if one slips up they are destined to meet in the last 16. Either way, this is a fixture that will need no narrative, and yet Spain's inclusion of Costa will provide a further heightening of tensions and emotions.
The striker will be booed and chastised throughout the tournament in Brazil. Newspaper headlines will declare him a traitor and supporters will describe him as far worse, a population of 200 million urging him to fail through desperation for their first ever home World Cup success.
However, while such treatment and scrutiny may have an impact on some players, you suspect that in the case of Diego Costa, it will simply spur him on to succeed. In fact, he probably would not have it any other way.
