Everton manager Ronald Koeman has reportedly held discussions with Manchester City sporting director Txiki Begiristain to thrash out a transfer fee for John Stones.
The England international could become the most expensive defender in history should the Citizens meet the rumoured £51m asking price.
A deal for Stones has yet to have been struck but, according to The Mirror, Koeman and Begiristain - who know each other from their time together at Barcelona - have discussed a potential move.
Everton are said to want a straight cash bid for the 22-year-old, but could also be willing to take Wilfried Bony as part of the transfer to ease their own attacking worries.
Should Man City meet the Toffees' cash demands, Stones would usurp David Luiz - a £50m signing for Paris Saint-Germain in 2014 - as the world's costliest defender.