The 31-year-old is widely regarded as one of his nation's best-ever players, earning 105 caps since making his debut in 2009.
However, Alaba has been sidelined since suffering a serious knee injury while representing Los Blancos in December, keeping him out of action until at least the start of next season.
Not having Alaba at his disposal is a major blow to Austria and head coach Ralf Rangnick, who has transformed the country into one of the dark horses to go far in the competition.
Nevertheless, it has since been revealed that the national team skipper will link up with the squad in the role of 'a non-playing captain'.
What has Rangnick had to say?
Commenting on the decision, Rangnick said: "It is a great shame of course that he isn't available to us as a player. Over the last weeks I've have had close exchanges with David. He stressed he wanted very much to still be with us.
"Therefore, I am very happy to say this will be possible after a good discussion with his club Real Madrid."
What is the main news from the rest of the squad?
Red Bull Salzburg goalkeeper Alexander Schlager and RB Leipzig midfielder Xaver Schlager have also each sustained knee injuries and will miss the tournament.
The squad is still full of experience and notable names, though, including midfield trio Konrad Laimer, Marcel Sabitzer and Christoph Baumgartner.
Forward Marko Arnautovic, now a veteran of 111 caps, is also included, with West Bromwich Albion's Andreas Weimann the solitary representative from English football.
What are Austria's pre-tournament plans?
Fixtures against Serbia and Switzerland will take place on June 4 and June 8 respectively. Rangnick is required to reduce his squad numbers from 29 to 26 by June 7.
Austria have been drawn in a group alongside France, Poland and Netherlands, their first fixture scheduled for June 17.
Austria's 29-player provisional squad in full
Goalkeepers: Niklas Hedl (Rapid Vienna), Tobias Lawal (LASK Linz), Heinz Lindner (Union Saint-Gilloise), Patrick Pentz (Brondby)
Defenders: Flavius Daniliuc (Red Bull Salzburg), Kevin Danso (Lens), Stefan Lainer (Borussia Moenchengladbach), Philipp Lienhart (Freiburg), Phillipp Mwene (Mainz), Stefan Posch (Bologna), Leopold Querfeld (Rapid Vienna), Gernot Trauner (Feyenoord), Maximilian Wober (Borussia Moenchengladbach)
Midfielders: Thierno Ballo (Wolfsberg), Christoph Baumgartner (RB Leipzig), Florian Grillitsch (Hoffenheim), Marco Grull (Rapid Vienna), Florian Kainz (Cologne), Konrad Laimer (Bayern Munich), Alexander Prass (Sturm Graz), Marcel Sabitzer (Borussia Dortmund), Romano Schmid (Werder Bremen), Matthias Seidl (Rapid Vienna), Nicolas Seiwald (RB Leipzig), Patrick Wimmer (Wolfsburg)
Forwards: Marko Arnautovic (Inter Milan), Maximilian Entrup (Hartberg), Michael Gregoritsch (Freiburg), Andreas Weimann (West Bromwich Albion)