Jeremain Lens looks to be closing in on a move to Besiktas after the Turkish side finally stepped up their interest.
Having publicly confirmed their interest earlier in the summer, they are thought to have made an opening bid which Sunderland have knocked back.
Sunderland will not stand in the Dutchman’s way, providing their valuation is met.
The 29-year-old signed from Dynamo Kiev for £8 million and the Black Cats will want to recoup a chunk of that fee to allow Simon Grayson to invest in his squad.
Grayson admitted last weekend that moving players on will be crucial to bringing in new players, at least on a permanent basis. Lens is one of the biggest earners in the current squad.
Lens is likely to be keen on the move to Besiktas. The Turkish side are investing heavily in their squad this summer and have already brought in Pepe from Real Madrid.
His initial preference was to stay with Fenerbahce but financial fair play concerns meant they could not move and Besiktas would offer the chance to return to Istanbul.
Sunderland will know wait to see if Besiktas match their valuation.
Reports on Friday have also suggested that Sunderland could face competition to sign trialist Robbin Ruiter on a permanent deal.
Simon Grayson wants to bring the Dutchman in after an impressive two games against Bradford and Scunthorpe United.
Any deal is dependent on the 30-year-old’s wage demands, with Hull City and Burnley said to be monitoring the situation.
Burnley are likely to be looking for a new goalkeeper following Paul Robinson’s retirement, though Hull still have David Marshall and Allan McGregor on their books, as well as the emerging William Mannion.