The 26-year-old Hamburg player was celebrating his side retaining their Bundesliga status for another year when he fell onto a table, sustaining a deep cut in his back which has thrown his chances of making the squad into doubt.
"First we'll have to wait a week to see how the healing goes, then we'll see after that," Sweden coach Erik Hamren told a news conference after the squad was announced.
Sweden open their Euro 2016 Group E campaign against Ireland in Paris on June 13 before meeting Italy and Belgium.
"The doctors' prognosis is positive. I'm going to stay in hospital for a couple more days to keep the situation under control," Ekdal said in a statement.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Sweden's captain and record goal-scorer Zlatan Ibrahimovic could be partnered in attack by Emir Kujovic, who was top scorer in the 2015 Allsvenskan as his unfancied IFK Norrkoping side won the Swedish title.
"I think we have a good mix, with a world-class player taking a big responsibility for the team, as Zlatan is doing, but also the team taking a big responsibility for Zlatan," Hamren told reporters.
Also included is Benfica defender Victor Nilsson Lindelof, who scored the winning penalty in the final of the Euro Under-21 Championship last year before making his debut for the senior side against Turkey in March.
Five other members of the victorious U-21 side also made the cut: defender Ludwig Augustinsson, goalkeeper Patrik Carlgren, midfielders Oscar Lewicki and Oscar Hiljemark and striker John Guidetti.
(Reporting by Philip O'Connor; Editing by Catherine Evans)
