New Arsenal player, has promised to do his best for the club after joining Mikel Arteta’s side from Flamengo on Wednesday, Mari joined Arsenal on loan from Flamengo.
The Gunners will reportedly pay £4million to the Brazilian club now and £8million to make the arrangement permanent.
Mari becomes Arteta’s first signing as Arsenal manager.
The 26-year-old is presently hoping to repay the faith Arteta has shown in him.
“I’m glad to be here today and to have signed for a big club,” said Mari at his unveiling on Wednesday.
“I’m going to do my best to help my colleagues and the club.
“I’m a very professional player. I like working hard every day to achieve objectives.”
He included: “One thing I can control is working hard on a daily basis to help my team-mates to win football matches and repay the faith that Mikel and Arsenal have shown me by signing me to play here, so that’s my main objective.
“I want to take it one day at a time and achieve big things at Arsenal.”