Arsenal manager Arsene Wenger
The Brazilian suffered an ankle injury late on in Sunday's win over Manchester City in Gothenburg, meaning the Gunners are even shorter in defence with the Premier League opener against Liverpool fast approaching.
And Wenger has confirmed that the injury will see the player miss as much as two months.
Arsenal's Gabriel Paulista lies injured
"Gabriel has an ankle problem, and will be out for six to eight weeks," he is quoted as telling arsenal.com. "It is a bit better than we feared at the start."
The 25-year-old made 29 appearances in his first full season as an Arsenal player, regularly coming in for Per Mertesacker when the German was experiencing issues with form or fitness.
With the news that the former Werder Bremen man is also out for several months, it was expected that Gabriel would be able to slot into a defence that is already struggling to rush Laurent Koscielny back after his European Championships exploits.
Germany's Shkodran Mustafi celebrates with teammates after scoring
But now the ex Villarreal centre back has also been injured for the first couple of months of the season, it could see the Gunners push that bit harder for Valencia star Shkodran Mustafi.
According to Sky Sports, talks between the two clubs for his services are ongoing, and the 24-year-old has been excused from a friendly on Wednesday night against a Nigerian All-Star side.
It already looks likely that at least one of the club's two young defenders, Calum Chambers or Rob Holding, will feature against Liverpool, and Wenger will be eager to get the deal done for Mustafi over the line as soon as possible so he has experienced options for the opening Premier League months.
Arsenal's Rob Holding celebrates scoring a goal