Speaking in his press conference ahead of Sunday's clash at the Emirates, the Gunners boss said: "Gabi unfortunately picked up an injury with the Brazil national team and he's going to be out for weeks. We need to have another scan next Wednesday, and we'll have the timeline probably much clearer than we have at the moment.
Gabriel joins Martin Odegaard, Noni Madueke, Kai Havertz, Gabriel Martinelli, and Viktor Gyokeres in the treatment room.
Elsewhere, Calafiori is a doubt for the game after returning early from his international duties with Italy.
"He wasn't available [for the international break], he's been carrying a few things and we had to bring him back," Arteta explained. "He hasn't trained yet. Tomorrow we have another training session and we'll see how he is."