Besiktas have been linked with Trabzonspor’s centre back Mustafa Yumlu.
The Black Eagles are looking to strengthen their defence in January.
Slaven Bilic has instructed the club to bring in a right back and a centre back.
Yumlu was left out of the Trabzonspor squad by Vahid Halilhodžić and hasn’t been recalled by the clubs new manager Ersun Yanal.
The 27-year-old centre back’s contract with Trabzonspor runs out in June 2016.
Yumlu has made four appearances for Tarbzonspor this season.