By . Simon Jones . Swansea City have rejected a £4million bid from Sunderland for Ashley Williams and are keen on Levante midfielder Pape Diop who is valued at £3m. The Wales international is stalling on a new contract and looks set to leave the Liberty Stadium this summer. One in, one out? Ashely Williams could leave with defensive midfielder Pape Diop (right) eyed by Swansea . Williams, 29, has a year left on his deal at Swansea, and manager Garry Monk has not given up hope of signing him to a new deal. But if an agreement can't be reached the Swans will look to sell their skipper to avoid losing him for nothing next summer.
Sunderland have bid £4m for the centre half, but Swansea rejected the bid . The south Wales club also want Levante's Pape Diop, who is valued at £3m .