The forward, who totalled 58 points in 77 appearances for the San Jose Sharks this season, received a bad cut to the hand in Sweden's 4-2 win over Czech Republic on Saturday as part of the Czech Hockey Games, serving as a warm-up to the World Championship.
It was later confirmed that Eklund has been ruled out for three months, with the Sweden national team - Tre Kronor - taking to X to confirm the 22-year-old will play no part in the tournament.
It was due to be Eklund's first World Championship, despite making his senior international debut in 2021.
That leaves 25 players on Sam Hallam's long list for the World Championship, the maximum that can be named for the event.
That includes 10 NHL players, including Eklund's San Jose teammate Alexander Wennberg.
Sweden took bronze at last year's World Championship, and begin their campaign to go at least one better when they play Slovakia in Group A on Friday.
All Group A matches will take place at Stockholm's Avicii Arena, while Denmark's Jyske Bank Boxen in Herning is the venue for Group B. The two venues host two Quarter-Finals each before Stockholm hosts the Semi-Finals and medal matches.