The former Manchester United star only linked up with the Turkish side 98 days ago on a free transfer from Old Trafford.
But his time in Istanbul could already be over before it has even properly began.
The 29-year-old started in the club's recent clash against rivals Fenerbahce, where they lost 3-1 to leave them fifth in the Super Lig table.
And Besiktas have now announced his exclusion from the squad, along with star striker Vincent Aboubakar.
Right-back Valentin Rosier, ex-Leicester winger Rachid Ghezzal and midfielder Jean Onana have also been hit with the same fate.
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A Besiktas club statement read: "Information from our club.
"Five players from our Football A Team have been excluded from the squad.
"Our Football Teams General Coordinator Samet Aybaba announced that Vincent Aboubakar, Valentin Rosier, Eric Bailly, Rachid Ghezzal and Jean Onana were excluded from the squad due to poor performance and incompatibility within the team.
"Our work on the new staff structure continues. We respectfully present it to the public."
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Just like his time at United, Bailly has been plagued by injuries this season, which has limited him to just five league appearances.
In his seven years at the Theatre of Dreams, he was restricted to just 113 matches in all competitions.
Post-match press conference: Erik ten Hag (Premier League: Manchester United 0-3 Bournemouth)
He never managed to feature more than 25 times in a single Premier League campaign, and failed to make five outings in two out of his last three years.
Erik ten Hag shipped him off on loan to Marseille last term, where he put a player in hospital following a kick to the chest.
It remains to be seen whether the Ivory Coast international will be on the lookout for a new club when the transfer market reopens in January.