The Ivorian defender has joined Besiktas, moving to Istanbul on a one-year contract.
Bailly is reported to have made the switch to Turkey for no fee, despite his previous deal at Old Trafford not expiring until next summer.
United have made the decision to part with Bailly on a permanent basis despite experiencing something of a defensive selection crisis at present, with key centre-back Raphael Varane currently sidelined for several weeks through injury.
Lisandro Martinez and Victor Lindelof were both forced off early in Sunday’s dramatic 3-1 Premier League defeat by Arsenal at the Emirates Stadium through injury and illness respectively, while the likes of left-back duo Luke Shaw - who also filled in as a makeshift centre-back under Erik ten Hag on a number of occasions last term - and Tyrell Malacia are also in the treatment room along with a host of other players including Mason Mount, Scott McTominay, Tom Heaton, Kobbie Mainoo and Amad Diallo.
United’s issues in defence meant that they saw out the game against Arsenal with Harry Maguire and the recently re-signed Jonny Evans, 35, as their centre-back pairing, Ten Hag down to his fourth and fifth-choice options just four games into the new Premier League campaign.
But despite those problems Bailly was evidently never considered as a potential option for United, having last played for the club in December 2021 and not at all under Ten Hag’s stewardship. The 29-year-old spent last season on loan in France with Marseille, making only 23 appearances. He did not figure in United’s plans during pre-season and was .left behind from their US tour.
Beşiktaş’a Hoş Geldin Eric Bailly
Kulübümüz, Fildişili defans oyuncusu Eric Bailly’nin nihai transferi hususunda Manchester United ile anlaşmaya varmıştır.
Kulübümüze önemli hizmetlerde bulunacağına inandığımız Eric Bailly’e şanlı formamızla üstün başarılar diler, kamuoyunun… pic.twitter.com/fQPb59vyzb
— Beşiktaş JK (@Besiktas) September 4, 2023
Bailly initially joined United from LaLiga outfit Villarreal for a fee of around £30million in the summer of 2016, becoming then manager Jose Mourinho’s first signing after being appointed to replace Louis van Gaal in the Old Trafford dugout.
He made 113 appearances for the club across all competitions in total, winning both the Europa League and League Cup under Mourinho in 2016-17. He also lifted the Community Shield on his debut in 2016 and finished as a runner-up in the 2017/18 FA Cup and was part of the squad that reached another Europa League final in 2021.
Bailly, who has 49 senior international caps for the Ivory Coast, scored his only United goal against Swansea in 2017 and frequently struggled with injury issues during his seven years at the club.
"Our club has reached an agreement with Manchester United for the final transfer of Ivorian defender Eric Bailly,” Besiktas said.
"We wish Eric Bailly, who we believe will provide important services to our club, great success with our glorious jersey, and present it to the public with our respect."
United said in their own statement: “Eric Bailly has left Manchester United to join Turkish Super Lig side Besiktas on a permanent transfer.
“Everyone at United thanks Eric for his contribution while at the club and wishes him all the best for the future.”
Though the transfer window in England closed on Friday night, clubs in Turkey still have until September 15 to make new signings.
Galatasaray completed a double deal with Tottenham for Tanguy Ndombele and Davinson Sanchez on Monday, with the reigning Super Lig champions having raced to get those signings over the line to make the squad registration deadline for the group stage of this season’s Champions League.
Senol Gunes’ Besiktas and rivals Fenerbahce are both in the third-tier Europa Conference League this term after finishing third and second respectively in 2022/23.
Besiktas, currently fourth in the Super Lig after an unbeaten start to the new season, have already signed the likes of Alex Oxlade-Chamberlain, Arthur Masuaku, Daniel Amartey and Milot Rashica from English clubs this summer and are reportedly also set to clinch a deal for Arsenal exile and former record signing Nicolas Pepe.
Bailly follows Fred to Turkey after his former United team-mate joined Fenerbahce in a £13m deal last month, while Galatasaray have also added the likes of Wilfried Zaha and Hakim Ziyech to their ranks this summer.
Meanwhile, United signed Turkish goalkeeper Altay Bayindir from Fenerbahce for £4.3m on deadline day having needed a new back-up to No1 Andre Onana with Dean Henderson joining Crystal Palace.