De Gea among Spain’s uncapped call-ups
De Gea impressed for the U-21s as they claimed the continental crown in last year but he has never before earned inclusion to the full squad.
Del Bosque's 21-man squad does not include any Barcelona or Athletic Bilbao players as they meet in the Copa del Rey final on 25 May.
Chelsea's Fernando Torres and Juan Mata are also absent due to their participation in the UEFA Champions League final on Saturday.
The final 23-man squad to travel to Poland and Ukraine will be named on 27 May.
Goalkeepers: Casillas (Real Madrid), Reina (Liverpool), De Gea (Man United).
Defenders: Arbeloa (Real Madrid), Ramos (Real Madrid), Albiol (Real Madrid), Alba (Valencia), Monreal (Malaga), Torres (Atletico Madrid); Dominguez (Atletico Madrid).
Midfielders: Alonso (Real Madrid), Cazorla (Malaga), Etxebarria (Real Betis), Isco (Malaga), Garcia (Benfica), Soriano (Villarreal) Silva (Man City), Navas (Sevilla).
Forwards: Negredo (Sevilla), Soldado (Valencia); Lopez (Atletico).