Spain coach Vicente del Bosque will name his squad for the upcoming friendly against Italy on Friday, and it will give the clearest indication yet of the team that will go to Brazil to defend their World Cup title.
Most of the speculation centres on whether Brazilian-born Diego Costa, a Spanish naturalised citizen, will be there when Del Bosque announces his list.
Del Bosque called up Diego Costa for a pair of November friendlies but injury kept the Atletico Madrid striker sidelined.
"No one, I mean absolutely no one, has seen their chances of going to Brazil written off," Del Bosque said. "Diego Costa's style of play and goals lend voice to his qualities."
There are questions over whether Diego Costa can fit in with a team whose nucleus in the World Cup win and back-to-back European Championships contains so many Real Madrid players, with whom the striker has had his share of skirmishes. Del Bosque criticized players from both teams for their actions following a recent Copa del Rey series.
"That's just my way of playing. I'm no saint," Diego Costa said.
Spain's myriad attacking options have left Del Bosque in a difficult spot, with Alvaro Negredo, Fernando Torres and Fernando Llorente among the choices. David Villa's chances may be slipping away, while Real Madrid forward Jese Rodriguez is forcing himself into contention.
Diego Costa has not played a competitive match for Spain so he could still opt for Brazil, who have just strikers Fred and Jo to choose from.
Del Bosque will be hard-pressed to overlook Bayern Munich midfielder Thiago Alcantara for the June 12-July 13 tournament. His inclusion could see Madrid's Isco or Manchester United playmaker Juan Mata being left out.
Also on Thursday, Spain announced they would play Bolivia at Sevilla's Sanchez Pizjuan Stadium on May 30 in an international friendly.