The player, in an Instagram post on Thursday night, said it was time to take up a new challenge.
The former Tottenham defender is reported to be heading to Italy to join Udinese in Serie A.
The development followed several reports from Italy claiming the former Gent defender has agreed on a deal with Udinese.
The Italian side recently lost their veteran centre-back and captain Danilo to Bologna.
“I want to say a big thank you to everyone in Bursa and Bursaspor especially my teammates and staff for everything,” Troost-Ekong posted on Instagram.
“I will always have great memories of my time in Turkey as a player but also as a man.
“However, the time has come for a new step in my career. I want to wish Bursaspor a great season and I will now follow the team as a fan.
“So, of course, lastly I want to say a special thank you to Texas and all the fans who supported me and the team. I will remain one of you now.”