Norway captain Martin Odegaard injured an ankle ahead of a key series of games for his club Arsenal.
Odegaard covered his face with his hands while being treated on the field midway through the second half of a Nations League game against Austria on Monday.
He appeared to turn awkwardly on his left ankle in a tough challenge with Austria midfielder Christoph Baumgartner as both chased and stretched for a loose ball.
Odegaard limped out of the game two minutes later and was consoled by his teammate Erling Haaland.
"It looked bad in the dressing room, too," Norway coach Stale Solbakken told broadcaster TV 2.
"He didn't have the chance to continue."
Odegaard was due to return from national team duty into a tough week of away games for Arsenal.
The Gunners first go to London rival Tottenham on Sunday then open their Champions League program at Atalanta, the Europa League winner, four days later in Italy. A visit to Manchester City completes a gruelling week on September 22.
Norway