Arsenal and Norway midfielder Martin Edegor was injured in the Nations League match against Austria (2-1) and left the field early.
According to Football London, the 25-year-old twisted his ankle and may miss 4 to 6 weeks.
"In the locker room, Martin Edegor's injury looked bad," said head coach Stole Solbakken.
It will be recalled that on September 15, the Gunners will play away to Tottenham, and on September 22, they will meet Manchester City. Also, the main stage of the Champions League starts next week.