Everton have reportedly placed an £18m price tag on left-back Leighton Baines.
The Toffees have taken the step amid speculation that Manchester United were preparing to return with an improved offer for the England international.
The Red Devils are thought to have bid around £10m for the defender a couple of weeks ago, but Everton manager Roberto Martinez would like to receive nearer £20m before he would consider parting with the 28-year-old, according to Sky Sports News.
It is believed that while Baines would consider a move to Old Trafford, he is not prepared to force through a switch by handing in a transfer request.