Sako is out of contract at English Championship side Wolves, prompting interest from West Brom, Leicester City, Aston Villa and Everton among others.
The Mali wide man enjoyed a great 2014/2015 campaign, netting 15 goals and assisting a further seven as the club missed out on a play-off spot on goal difference.
Furthermore, Besiktas have also been linked with Newcastle United striker Cisse - the 30-year-old is seen as a possible replacement for fellow Senegal international Demba Ba, who is looking to return to England.