Gabriel Magalhaes said the influence of Arsenal manager Mikel Arteta and technical director Edu convinced him to join the Gunners after completing a reported £22 million ($30 million) move from Lille on Tuesday.
The 22-year-old defender was also in demand from Manchester United and Napoli after impressing as Lille finished fourth in the curtailed 2019/20 Ligue 1 season.
Gabriel adds to Arsenal's growing Brazilian contingent since the club's former midfielder Edu left his role as coordinator for the Brazilian national team to become technical director last year.