Martin Odegaard had to pull out of Arsenal’s pre-season friendly against Nurnberg after suffering an injury in the warm-up.
The Gunners issued an update saying that their captain had suffered ‘a knock’ just ahead of kick-off and had been replaced in the starting XI by Fabio Vieria.
It is not yet clear how long Odegaard could be out for.
Arsenal leave for their US tour on Sunday where they will play three games, against Manchester United, Barcelona and the MLS All Stars.
Mikel Arteta’s side were also without several other players for the game against Nurnberg.
Gabriel Martinelli, Takehiro Tomiyasu and Oleksandr Zinchenko were not involved in the squad, despite having made the trip to Germany.
All three players missed the closing stages of last season and are now being carefully managed as they return to full fitness.
Martinelli and Tomiyasu could be back for the first game of the US tour, but Zinchenko could be out for a bit longer.
Reporters at the game in Germany have been told the Ukrainian could miss the next two matches as Arsenal ease him back into action.
Rob Holding (muscle tightness) and Marquinhos (knock) also sat out the Nurnberg fixture, but their absences are believed to be purely precautionary.