Arsenal have announced Edu as the club's first technical director.
The former midfielder rejoins the Gunners after leaving a similar role with the Brazil national team, who last week won the Copa America for the first time in 12 years.
Edu was part of the famous Invincibles squad that went a whole Premier League season unbeaten under Arsene Wenger in 2003-04.
And the 41-year-old will now be returning to the club as the revamp of the backroom staff continues.
Arsenal said in a statement that Edu will "coordinate the work of our first-team coaching group, the academy and player scouting and recruitment in order to oversee the constant building-up and efficient strengthening of our squad".
Edu will work closely with head coach Unai Emery, whom he played for at Valencia.
"Arsenal has always had a special place in my heart and I'm thrilled to be returning to this great club in this new role," said the Brazilian.
"We have a strong squad and some very talented young players with fantastic people at every level. I'm looking forward to helping make a difference."
Head of football Raul Sanllehi added: "We're very excited that Edu is joining the team. He has great experience and technical football knowledge and most importantly is a true Arsenal man. He understands the club and what we stand for to our millions of fans around the world.
"His arrival is the final and very important part of the jigsaw in our development of a new football infrastructure to take us forward.
"He will be working closely with Unai Emery and the first-team coaches, and will play a relevant role leading our football vision and ensuring we have - and follow - a solid philosophy through all our football activities."