The striker played 90 minutes and scored in Sweden’s win over Romania on Friday. He will miss the rest of the Nations League window: games against Poland, Bosnia and Herzegovina and Romania.
Liverpool said Isak “will now be assessed by club medical staff at the AXA Training Centre.”
Isak joined from Newcastle United for a record £125 million in the summer of 2025. His first season was interrupted by injuries. This campaign he has four goals in five Premier League matches.
The club’s next league fixture is against Manchester City on 11 October. Whether he is available then depends on the assessment at Kirkby.
Sweden must finish the international break without their leading striker. Liverpool will treat the issue as precautionary until the medical staff report. After last season’s fitness problems, any absence is watched closely even when it is described as minor.