The other notable omission was Barcelona's 17-year-old striker Boban Krkic, who has complained of fatigue after his debut season.
"I spoke with Bojan and he told me he was physically and mentally tired and I trust him when he says he isn't in the best shape to come," Aragones added.
Villarreal were rewarded for an outstanding season, in which they pipped Barcelona to second place in La Liga, with places for Marcos Senna, Joan Capdevila and uncapped midfielder Santi Cazorla.
As well as Liverpool, Valencia also supply four players in defenders Raul Albiol and Carlos Marchena, midfielder David Silva and striker David Villa, with only three from Barcelona and two from Real Madrid.
Spain, who have gone 14 games undefeated, play friendlies against Peru on 31 May and USA on 4 June.
They kick off their Euro 2008 campaign in Austria and Switzerland against Russia on 10 June before facing Sweden on the 14th and defending champions Greece four days later.
The squad announcement had been delayed for 24 hours following the death of Spain's doctor, Genaro Borras, on Thursday.
Defenders: Raul Albiol (Valencia), Carlos Marchena (Valencia), Joan Capdevila (Villarreal), Sergio Ramos (Real Madrid), Juanito Gutierrez (Real Betis), Fernando Navarro (Mallorca), Carles Puyol (Barcelona), Alvaro Arbeloa (Liverpool)
Midfielders: Xavi Hernandez (FC Barcelona), Andres Iniesta (Barcelona), Cesc Fabregas (Arsenal), David Silva (Valencia), Xabi Alonso (Liverpool), Ruben De La Red (Getafe), Marcos Senna (Villarreal), Santi Cazorla (Villarreal)
Forwards: Fernando Torres (Liverpool), David Villa (Valencia), Daniel Guiza (Mallorca), Sergio Garcia (Zaragoza).
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