Marchand missed yesterday's final in the French championships in the 200-metre breaststroke - one of the disciplines in which he previously won Olympic gold and a final that also served as a qualifier for the European Championships.
The star has already secured his place at the European Championships in the 400-metre medley and was scheduled to qualify for five more events. So that won't be the case.
He could still be selected for more European Championships if all qualifying spots are not filled before the French Championships end, provided he has recovered from the injury.
The 24-year-old became one of France's great heroes during the 2024 Paris Olympics, where he won four gold medals on home soil.
