Besiktas are one of the frontrunners in the race for Sunderland playmaker Wahbi Khazri.
Khazri looks certain to leave the Black Cats this summer but has said that he is focusing only on Tunisia's World Cup prospects for the time being.
There is strong interest from France following a stellar season on loan at Stade Rennais, where Khazri impressed in an unfamiliar striking role.
The Turkish giants finished fourth in the Super Lig last season, meaning that they will play Europa League football next season.
They will sign Jeremain Lens on a permanent deal on July 1st, and Khazri could follow the Dutchman in making the switch from Wearside.
They have been interested in the 27-year-old throughout the summer and could firm up their interest with a bid in the coming weeks.
Khazri has had a disrupted build-up to the World Cup due to injury but is set to be fit to feature in Tunisia's opening game against England on Monday.
He is one of a crop of players from the Premier League era who Sunderland will be keen to move on this summer, with their wages not dropping further as a result of relegation to League One.
Alongside Paddy McNair, he is one of the club's biggest assets and could command a significant fee.