Jeremain Lens has been heavily linked with a move away from Sunderland this summer

Sunderland have turned down a bid from Turkish club Besiktas for their Dutch winger Jeremain Lens, according to Sky sources.

The 29-year-old joined the Black Cats from Dinamo Kiev, for £11m, in the summer of 2015.

He made 23 appearances for Sunderland - in all competitions - during his first season on Wearside before spending most of 2016/17 on loan at Fenerbahce.

Sky Sports News understand Sunderland are willing to sell Lens but that the Besiktas bid fell short of their valuation.