Ba has been linked with a number of Gulf Arab clubs over the past few months.
The 29-year-old striker joined the Black Eagles on a €6 million move from Chelsea this summer and already has 27 goals and seven assists in all competitions for Beşiktaş.
Ba is currently the second highest goalscorer in the Turkish Super Lig with 18 goals, four goals behind Bursaspor forward Fernandao who has scored 22 goals in the league.
The Black Eagles crashed out of the title race on Monday 18 May after losing 1-0 against Konyaspor at the Osmanlı stadium in Ankara.
The Istanbul giants take on Galatasaray next in the derby and can still finish as runners up if they win their next two games and if Fenerbahçe drop points over the next fortnight.
Bilic has yet to record a derby victory against Fenerbahçe or Galatasaray since joining Beşiktaş in 2013.