Besiktas are rivaling CSKA Moscow for Everton winger Niko Vlasic.
The Liverpool Echo says Vlasic has spent this season on loan with CSKA and has impressed with eight goals and seven assists, including a strike against Real Madrid in the Champions League.
The Croatian international asked for a move away from Goodison last summer with Marco Silva unable to offer him any guarantees over playing time.
It is understood that Vlasic now wants to leave Everton permanently.
CSKA have made no secret of their desire to turn his loan into a permanent move but now face competition from Besiktas for his services.