Salzburg - Real Madrid midfielder Isco and Atletico's Saul Niguez on Tuesday missed the cut for Vicente Del Bosque's final 23-man Spain squad for Euro 2016 that does include Real's Lucas.
"We tried to balance out the squad," Del Bosque said at a press conference at the Austrian city of Salzburg.
"I believe that with the 23 chosen, we can cope with any emergency."
Del Bosque added: "The players who've missed out have the standard to be there, but I can only take 23 of them."
Having played in Real's extra-time win on penalties over Atletico on Saturday, Real's Sergio Ramos and Lucas Vazquez, and Atletico's Juanfran and Koke will be the last to join up with the Spanish squad on June 4.
Arsenal defender Hector Bellerin, an absentee from the initial 25-strong list announced on May 17, was also included in the final squad following Real defender Dani Carvajal's injury in the Champions League final.
Spain play South Korea on Wednesday close to Salzburg before taking on Georgia in its final pre-Euro warm-up game in Getafe, back in Spain.
Spain squad for Euro 2016
Goalkeepers: Iker Casillas (Porto), David de Gea (Manchester United), Sergio Rico (Sevilla)
Defenders: Marc Bartra (Barcelona), Jordi Alba (Barcelona), Gerard Pique (Barcelona), Cesar Azpilicueta (Chelsea), Hector Bellerin (Arsenal), Sergio Ramos (Real Madrid), Juanfran (Atletico Madrid)
Midfielders: Sergio Busquets (Barcelona), Mikel San Jose (Athletic Bilbao), Cesc Fabregas (Chelsea), Thiago Alcantara (Bayern Munich), Bruno Soriano (Villarreal), Andres Iniesta (Barcelona), Koke (Atletico Madrid)
Forwards: Pedro (Chelsea), David Silva (Manchester City), Alvaro Morata (Juventus), Aritz Aduriz (Athletic Bilbao), Nolito (Celta Vigo), Lucas Vazquez (Real Madrid).