Spain coach Vicente del Bosque says he has yet to decide who will start in goal and up front when the world champions get their Confederations Cup campaign underway against Uruguay on Sunday.
Del Bosque's men rounded off their preparations for the tournament with a 2-0 win over the Republic of Ireland in New York on Tuesday thanks to goals from Roberto Soldado and Juan Mata.
But they were also thankful for two fine saves from captain Iker Casillas in the second-half.
The Real Madrid veteran continues to shine on his comeback after being frozen out by Jose Mourinho towards the end of the season at the Santiago Bernabeu.
But despite the key contributions from Soldado and Casillas, Del Bosque insisted their places in the side were not guaranteed.
"The number nine works when the team works. I am not going to say who is going to start," he told a press conference after the match.
"Soldado has had two games in which he has shown himself to be very incisive, but (Fernando) Torres and (David) Villa have been too.
"There are no starters or substitutes because all of them are primary figures at their clubs and it is difficult to choose because they are all very good.
"Iker had a very good performance, but any of the three goalkeepers could play. On the 16th you will see."
Victory extended Spain's unbeaten run to 21 games stretching back to November 2011 and Del Bosque believes they will arrive in Brazil full of confidence.
"We played well. We had possession and dominance and if we lacked something it was the final pass, but the victory was deserved and it would not have been unjust to have achieved it by another goal.
"We arrive with confidence, in a good moment and with excitement, but there are seven teams that are going for the title and they have the same chance."
After facing Uruguay in Recife, Spain will also take on Tahiti in Rio on June 20 and then African champions Nigeria three days later in Fortaleza.