West Ham are demanding huge money from Manchester United to sell Issa Diop.
The Mirror says United are targeting Diop - but could be forced to pay as much as £75million to prise him away from the London Stadium.
The defiant Hammers are insistent their 22-year-old star defender is not for sale with Manuel Pellegrini desperate to keep him after a highly promising first season at the club.
Although an unlikely swap bid for United's France winger Anthony Martial has been mooted - and predictably rejected - it is understood West Ham have only done so to indicate their unwillingness to sell Diop.
The player himself has not put any pressure on the club to force the move and revealed in an exclusive interview last season that he is keen to build on his debut campaign in east London.