Sunderland have reportedly demanded that West Ham United increase their bid for Connor Wickham to £8m.
The Black Cats are said to have turned down a £5m offer for the striker, who scored seven goals for Gus Poyet's side last season, from West Ham earlier today.
The Telegraph reports that Sunderland are keen to recover the £8m that they paid Ipswich Town for Wickham in 2011.
The 21-year-old is heading into the final year of his contract at the Stadium of Light.