Chelsea have upped their bid for John Stones, but may ultimately be forced to pay a record fee for the England defender.
The London club have offered in the region of £26m for the Everton centre-back, according to ESPN, after seeing an initial £20m offer knocked back.
The record fee for an English defender is the £30m Manchester United paid for Rio Ferdinand, and Chelsea may ultimately be forced to go above this figure to get their man.
Stones moved to Goodison Park for just £3m in January 2013 and has established himself as a regular for the Merseyside club, while also breaking into the senior England squad.
If Everton accept Chelsea’s latest bid it would make the 21-year-old the sixth most expensive Englishman in football history.
Jose Mourinho has suggested Chelsea may have a ceiling on what they are prepared to offer, though, admitting “for ourselves there are certain rules”.