The Atletico Madrid striker has been in blistering form throughout the past campaign having notched in with 36 goals in 50 appearances for his club in all competitions. Going into the World Cup, Costa is believed to be Spain’s preferred choice to lead the line as La Roja aim to defend their crown but has suffered a knee injury in recent weeks which makes him a doubt for the competition. Costa could have played for Brazil but opted to play for Spain and made his debut in a 1-0 win over Italy in March. Del Bosque is hoping to call him up to the final 23-man squad which has to be submitted to FIFA by 2 June but the striker faces a race against time.“Until the 2nd (June) we have time to create the list. I am moderately optimistic (about Diego Costa),” he told Mediaset. His comments follow those of doctor  Pedro Guilln who did not discount the Brazilian-born forward’s chances of making the World Cup but stated that “he will have to rest for at least two weeks” on Cadena Cope radio.