Sunderland have turned down a bid for their striker from West Ham.
The 21-year-old's heroics almost single-handedly dragged the Black Cats from the brink of relegation to Premier League survival last season.
It appears he is unlikely to sign an extension to his contract which only has 12 months to run, and Gus Poyet told him "sign new deal soon or be sold".
But he is holding firm and is looking to pastures new.
Sunderland want around £8m but the Hammers have only offered half of that.
Newcastle had hopes of signing the England U-21 international last month, but the asking price frightened off Mike Ashley.