Chelsea are reportedly weighing up a fourth bid for England international John Stones.
The defending Premier League champions, who currently sit just three points above the bottom three after their opening 12 games, failed to sign the Everton centre-half during the summer transfer window after relentless speculation.
The 21-year-old, who has now earned seven international caps, has made 13 appearances in all competitions for the Toffees so far this season.
Blues boss Jose Mourinho is eager to bring highly-rated Stones to Stamford Bridge in the January transfer window as a replacement for failed addition Papy Djilobodji.
The 26-year-old fellow defender has made just one first-team appearance for the club since joining from French outfit Nantes during the summer.