The New York City forward, who is his country's leading goalscorer with 59 in 97 appearances, has not played for the national team since the dismal defence of their World Cup in Brazil in 2014.
Villa himself said last month that he remains optimistic of regaining his place and surpassing the 100-cap mark, and Del Bosque has left the door open to a place at the finals in France for one of the few players who remain from the victorious Euro 2008 squad.
"Nobody is excluded," he told Radio Marca when asked about Villa's chances.
"Only five or six players from 2008 are still going. I like the term 'quiet revolution'."
Del Bosque has also backed Diego Costa to keep his spot if he maintains form and fitness for Chelsea in the coming months and suggested that Atletico Madrid prospect Saul Niguez could also earn a place.
"If Costa looks good, he'll go to the Euros," he said. "We'll see what happens with Saul."
Del Bosque stated in December that he does not intend to stay in his post beyond the 2016 finals and he has stressed that his plan remains to allow a successor to take charge for the 2018 World Cup in Russia.
"At the moment I don't see myself on the bench at the World Cup in Russia, but there's a lot of time to arrange a possible natural replacement," he added.
"I have an excellent relationship with all the people in the Spanish Football Federation. I'll be where they ask me to be.
"I don't want to go against a majority opinion. I'm 65 and I'm not going to spend my life on the bench."