The centre-back, who played in the Seleção's 2-0 friendly win over Senegal at the Emirates Stadium before being withdrawn due to sustaining the injury, has played every minute of Arsenal’s Premier League campaign so far this season.
The Gunners currently sit 4 points clear of Manchester City at the Premier League summit, but Arteta’s side are now likely to be without their star defender for the hectic festive period, starting with the visit of Tottenham Hotspur on Sunday.
Speaking at his press conference ahead of the north London derby, Arteta said: “Gabby, 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 – I think it’s next Wednesday. Then we will have the timeline probably much more clear than we have at the moment.
“It’s clearly a blow because it’s our leader in our backline, and to lose him is obviously never a positive thing. The good thing is that we have very good options, and people have to stand up now and do the job.”
There were further injury concerns among Arsenal’s defensive ranks as Riccardo Calafiori missed Italy’s fixtures over the international break with a suspected injury picked up while with the national side.
The left back, who has started all 11 of the Gunners’ Premier League fixtures this campaign, hasn’t yet trained since returning from international duty, as Arteta revealed.
“He’s been carrying a few things, and we had to bring him back. He hasn’t trained yet, so tomorrow we have another training session, and we’ll see how he is,” said the Arsenal boss.
“He’s been dealing with a little issue. He played, and we rested him \[in the Champions League\] because of that. When he got into the last game and had to travel with the national team, they were very understanding of that issue, and that’s when they allowed him to come back.”
It remains to be seen whether several other first-team names will return in time for the clash with Spurs at the Emirates Stadium on Sunday.
Club captain Martin Odegaard, Viktor Gyokeres, Noni Madueke, Gabriel Martinelli and Kai Havertz have all been long-term absentees this season, and at the end of October, Arteta was hopeful that some of those players would be fit enough to return to action for this game.
The Arsenal boss was asked if he remains as optimistic about the prospect of those players returning to action this weekend, and he said: “I am, but it’s the final stage. Now is when they have contact around them, when they have to push into very unpredictable things that they haven’t done. I think they’re going to be with us soon. I don’t know if Sunday is going to be too soon.”
Arsenal host Spurs this weekend in the first game back from the international break, signalling the beginning of a tricky run for the Gunners ahead of crucial fixtures against Bayern Munich and Chelsea on the horizon.