Some horror tackles on the player on his debut in Brazil's match against Bolivia means he might have to rest. Although I still haven't found any news about Gabriel's current condition but the possibility of him resting for a few weeks is still possible and this could be a problem for Arsenal who are ready with some matches and a busy schedule.
Arsenal's coach Arteta was already starting games without him this season, so he will be able to adjust for the time being hopefully the injury is not going to be a long one. Kiwior will most likely be the one to start against Everton. Everton have had a bad start to the season, they may want to change it when they play against Arsenal.
Arteta's biggest hopes is that he will not have more players injured in this international duty.