He was linked with several clubs in the summer including Chelsea and Spurs and, speaking ahead of Saturday's north London derby, Arteta opened up on how the Gunners were able to secure his signature.
"Edu had a talk with him to express and project and what the club is about," the Spaniard told his pre-match press conference.
"He explained the role he would have at the club. I then spoke to him so it was a team effort and he clearly understood what we wanted to do.
"The relationship with him (Edu was general coordinator of the Brazil national team from 2016-2019) helped because we had that trust and then the decision was up to him."
Arteta also explained how he has picked him up after being omitted from the national team.
He said: "I understand how they are feeling how it has hit them and how can we help them. They just have to put their head down and take it on the chin, try and play at the level he's been playing at to make it even harder to leave him out."