The 70-year wait for a major trophy at St James' Park finally ended under Howe last season when his side lifted the Carabao Cup, and he also guided Newcastle United into the Champions League on two separate occasions during a tenure that comes to a close today at the age of 48. Newcastle have already lined up Al Ahli's Matthias Jaissle as his successor, with the German coach expected to be confirmed in the coming days.
Anthony Gordon's move to Barcelona and Sandro Tonali's switch to Tottenham Hotspur had already stripped two key names from Howe's squad list this summer, and Guimaraes' looming departure for Arsenal is reported to have been the final factor behind the manager's decision to step back from coaching altogether.
Reports emerged that Guimaraes, 28, had been left out of the travelling party for Newcastle's pre-season camp in Spain, a detail that hardened suspicions the Arsenal move is now close to being finalised. Talks between the two clubs have progressed significantly since The Sun first reported the north London club would need to pay north of £70m, with French outlet L'Equipe now indicating Arsenal have had a €90m (£77m) offer accepted after two lower bids were rejected, with personal terms on a contract running until 2031 already agreed.
The midfielder is reportedly waiting only for the clubs to finalise the fee before undergoing a medical.
As the two Premier League clubs worked to tie up the finer details, the Brazilian took to Instagram to pay tribute to his outgoing manager. He first shared the club's own farewell video for Howe, adding a short message of his own:
"King of this club! Thanks for everything you've done for us. I loved enjoying our time together. Thanks for [making] me a better player and person."
He then added a line that appeared to hint at his own impending departure: "No words I can say will really say how much I enjoyed being our player. Wish all the very best in your future, gaffer."
Guimaraes followed that with a photograph of himself alongside Howe and a longer, more personal tribute, posted in full below:
"Ed, how could I ever put into words how grateful I am to you? First of all, I want to thank you for bringing me to this club. Thank you for everything you've done for me, for helping me grow not only as a player, but more importantly as a person.
"You gave me the honour of being captain – of being your captain. That is something I will never forget and will carry with me for the rest of my life. Sharing the day-to-day with you and having you as my manager has been a privilege.
"I'm truly grateful for every opportunity, for the trust you placed in me, and for every moment we shared together. Without a doubt, you are one of the best managers I've ever had. Please know that my gratitude will always remain, and that you will always have a friend in me. Thank you for everything, I wish you and your family nothing but happiness, success and all the very best."
Guimaraes joined Newcastle from Lyon in 2022 and was handed the captaincy under Howe, going on to make over 150 appearances and establish himself as one of the Premier League's most influential midfielders during his four years on Tyneside.