Per the source, recently appointed Dutch manager Dick Advocaat is keen on bringing on Lens and is reported to have close ties to the player.
Advocaat already has two Dutch players at Fenerbahce in Van Persie and Van Der Wiel but wants to sign another player from his home country to reduce the settling in time he will require.
The former Netherlands national team assistant manager replaced Vitor Pereira just last week and the league campaign will start over the weekend.
NTV Spor pundit Guntekin Onay meanwhile recently confirmed that Besiktas are also keen on Lenes.
Besiktas would be able to offer Champions League football after winning the league title last season.
Lens joined Sunderland last summer on an £8 million move from Ukrainian giants Dynamo Kiev but struggled to settle in contributing to just six goals all season – three goals and three assists.
The 28-year-old Netherlands international does have another three-years remaining on his current contract.