Alonso has struggled with injuries in the second-half of the season and has not been given the all-clear by Madrid's doctors to take part in the competition which starts June 15, reports Xinhua.
Also left out of the team were mid-fielders Benat Extebarria and Javi Garcia as Spain coach Vicente Del Bosque released the final 23-man squad on Sunday.
Spain will travel to Brazil for their opening game of the tournament against Uruguay, June 16 in Recife.
Photos: Ajay Devgn, Parineeti, Tabu at 'Golmaal Again' trailer launch
Photos: 'Dangal' girls Sanya Malhotra, Fatima Sana Shaikh's dinner outing
Photos: Kareena Kapoor Khan's grand birthday bash
Photos: Salman Khan, Daisy Shah spotted at the Mumbai airport
Photos: Rakhi Sawant to play Honeypreet in Ram Rahim biopic