Spain boss Vicente del Bosque has said that Diego Costa is not guaranteed a spot in his squad for the 2014 World Cup.

The Atletico Madrid forward recently announced his decision to represent Spain and not Brazil – the country of his birth – at international level.

However, Del Bosque has insisted that he will judge the 25-year-old's performances throughout the season before making a decision.

"Diego Costa does not have unlimited credit. It is true that we feel a bit of an obligation, but the final decision will be based on his performances over the course of the season," Del Bosque told reporters at a press conference.

"It was a hard and risky decision for him as he changed his dream of playing for Brazil to defending Spain's honour instead.

"He brings healthy competition to the team in attack and we will select those who are the best. There are still enough matches to prepare for the World Cup and he will get his chance."

Costa has scored 13 league goals for Atletico so far this season.