Piero Hincapie and Cristhian Mosquera are both in contention to deputise for Gabriel when Arsenal host rivals Tottenham on Sunday (16:30 GMT).
“It’s clearly a blow because he’s our leader in our backline and to me it’s never a positive thing,” added Arteta.
“The good thing is that we have very good options and people have to stand up now and do the job.”
Gabriel, a £23.1m signing from Lille in 2020, has started all 11 of Arsenal’s Premier League matches this term.
Defender Riccardo Califiori is a doubt for the north London derby, having withdrawn from international duty with Italy with a hip problem.
The Italian is yet to train since returning to London but Arteta says he will be given every opportunity to prove his fitness.
“He has been carrying a few things,” said Arteta.
“He hasn’t trained yet. Tomorrow we have another training session, let’s see how he is.”
Swedish striker Viktor Gyokeres remains unavailable with a hamstring problem.
