Daniel Ståhl's Lithuanian competitor tore his pectoral muscle in March and was expected to miss the outdoor season. But the injury has healed faster than expected and he had planned to make a comeback in Stockholm on Sunday.
But Alekna has been stopped by his university in the United States.
Because he has been injured, there is a special clause that says he is not allowed to compete for the duration of the semester, even if he is fit to compete, Stockholmsgalan competition director Jan Kowalski told Expressen.
The semester only ends after Sunday's competitions.
Daniel Ståhl will still face tough opposition at the Stockholm Stadium from, among others, world and European champion Kristjan Ceh of Slovenia and Olympic bronze medalist Matthew Denny of Australia.
