Diego Costa has declared that he is fully fit ahead of Spain's opening World Cup match against the Netherlands on Friday.

The Atletico Madrid striker has been battling a hamstring problem recently, but he believes that he is ready to take a full part in the Group B clash after playing for the majority of a 2-0 victory over El Salvador on Saturday.

"I needed the match with El Salvador," Costa told reporters in Brazil. "Now I am fine and I will have no problems for the first match."

Spain will also face Chile and Australia in Group B.