On Monday morning, it was reported that the 46-year-old - who was a member of the Gunners' 2003-04 Invincibles squad under Arsene Wenger - had surprisingly decided to step down from his position.
Edu has been a part of the furniture at Arsenal for five years, returning to North London as a technical director in 2019 and helping to oversee Mikel Arteta's arrival as head coach following the sacking of Unai Emery.
The Brazilian was then promoted to the role of sporting director in 2022, becoming Arsenal's first-ever, and he has forged an extremely close relationship with Arteta during their rise back to the top of the English game.
However, amid rumours that Edu is being headhunted for a position at Evangelos Marinakis's group of clubs - where The Independent claims he could treble his wages - the Gunners have now announced the former midfielder's immediate resignation.
Edu to "pursue a different challenge" after Arsenal exit
"This was an incredibly hard decision to make," Edu told the official Arsenal website. "Arsenal has given me the opportunity to work with so many amazing people and the chance to be a part of something so special in the club's history.
"It has been a special journey and I thank Stan, Josh, Tim and Lord Harris for the support they've given me. I've loved working with so many great colleagues across our men's, women's and academy teams, especially Mikel, who has become a great friend.
"Now it is time to pursue a different challenge. Arsenal will always remain in my heart. I wish the club and its supporters only good things and all the very best."
Arsenal co-owner Josh Kroenke also paid tribute to Edu's time at Arsenal, albeit while insisting that "change and evolution" is inevitable in North London, adding: "We respect Edu's decision and thank him for his immense contribution and dedication to drive the club forward.
"Everyone at the club wishes him well. We are all so fond of him and the positive energy he brings to everything and everyone. Change and evolution is a part of our club. We remain focused on our strategy and winning major trophies. Our succession plan will reflect this continued ambition."
Edu's Arsenal journey epitomises rise of Arteta's Gunners
Flash back to the middle of the 2021-22 season, where many Gooners may have only been too happy to see the back of Edu after Arsenal terminated Pierre-Emerick Aubameyang's contract without replacing him.
The Gunners' indifferent performances on the pitch were not helping matters either, but as Arsenal have grown into Premier League challengers once more, Edu has established a reputation as one of the finest sporting directors around.
Since his official promotion to sporting director in late 2022, Arsenal have secured the transformative signing of Declan Rice, while also adding star quality in Mikel Merino, Riccardo Calafiori, David Raya and Kai Havertz to the ranks.
Edu also helped oversee the arrivals of Martin Odegaard, Ben White and Gabriel Magalhaes in his technical director role, not to mention securing contract renewals for a surfeit of Arteta's most prized possessions; the aforementioned trio, Bukayo Saka, William Saliba and Gabriel Martinelli are among those to have agreed new terms over the past couple of years.
The 46-year-old was honoured for his stellar work at the 2023 Golden Boy Awards, where he was named Europe's Best Sporting Director after the Gunners finished second in the 2022-23 Premier League season.
However, at a time when the Gunners have failed to win any of their last three Premier League games, Edu's exit will raise questions about the direction the club is heading in off the field, while also depriving Arteta of one of his closest allies.