Arsenal captain Martin Odegaard limped off as Manchester City forward Erling Haaland scored a late winner for Norway against Austria in the Nations League.
Odegaard went down in pain after hurting his ankle following a foul by Christoph Baumgartner midway through the second half.
The midfielder could now be a doubt for Sunday's north London derby, with the Gunners already missing Declan Rice for the game against Tottenham through suspension.
"It looked painful in the locker room," Norway boss Stale Solbakken told TV2.
"We know it was an ankle sprain. With luck it can turn out OK, if the ligaments aren't torn, but I'm not really sure [Arsenal boss Mikel] Arteta will call me tonight to praise me.”
Team doctor Ola Sand, added: "He's got a small ankle sprain. We will see, maybe we use ultrasound to look at it. If we are unsure, there will be an MRI tomorrow."
Odegaard was injured when the score was 1-1, with Felix Myhre's opener for Norway having been cancelled out by Marcel Sabitzer in the first half.
The League B Group 3 match looked to be heading to a draw but Haaland, who has scored seven goals for Manchester City already this season, showed good strength and composure to control a ball into the box and then finish.
After Sunday's derby, Arsenal play Atalanta in the Champions League on 19 September and then face Premier League leaders Manchester City at Etihad Stadium on 22 September.