Spain coach Vicente del Bosque said his definitive squad for the European Championships will be named after the Copa del Rey final between Athletic Club Bilbao and FC Barcelona.
Several players from both clubs who will be playing the cup final on May 25 are certain to be included in the final squad, reported Xinhua.
Meanwhile, the coach, who led the defending European Champions to the 2010 World Cup triumph, will give a preliminary list on May 16 in which the names of players from Bilbao, Barcelona and Chelsea's Juan Mata and Fernando Torres will not feature.
He admitted that naming the squad would not be easy.
"It is normal for the players to be normal but we will have to take painful decisions because the team is the most important thing. I have some doubts, but also clear with some things," he said.
David Villa, who broke his leg in December, hasn't returned to action causing concerns over his fitness. He has been the highest goal scorer for the Spanish national side.
"I spoke with his coach (Pep Guardiola) and enquired about his condition and will wait until the last moment," said Del Bosque, who added that former Real Madrid striker Raul Gonzalez, who has enjoyed two successful years with Schalke 04 in Germany, is also up for consideration.
The Spain coach spoke of the need to have a good atmosphere in the squad.
Recognizing threats from sides such as Italy, France, Germany and Holland, he felt defending their Euro 2008 title would be a challenging task.
"We have an historic challenge ahead of us if we win the European Championship for the second successive time. Nobody has done that and it is a challenge without precedent," he said.