By SABC Sport
14th December 2023
The 29-year-old Ivory Coast defender joined the Turkish side from Manchester United this season, having spent last term on loan at Marseille.
He went on to play eight games in total for Besiktas, with his brief time at the club also hindered by injury.
But the player's agent believes his clinet's "rights are being violated" after he was removed from first team duties.
Bailly is one of five players dropped from the squad.
Agent Rafaela Pimenta said: "We are shocked and it took us by surprise.
"We are preparing our reaction since we know Eric has done nothing wrong. The player's rights are being violated and we will make sure to protect him"
Vincent Aboubakar, Rachid Ghezzal, Jean Onana and Valentin Rosier have also been removed from the squad.
Besiktas president Hasan Arat told the AFP news agency: "Our number one priority is to build a better team - we will fill the holes in our squad during the [winter] break."