Chelsea's persistent pursuit of Everton defender John Stones has taken a dramatic twist.

The English international has reportedly handed in a transfer request at Goodison Park as he attempts to force through the move before the close of the transfer window.

Everton are believed to have recently rejected a £30M offer and manager Roberto Martinez has hinted that they could insist on the player staying at the club even if he did request a move.

With question marks over the form of Chelsea's defenders, Jose Mourinho is believed to be very keen on bolstering the back-line with an eye to the future, with Stones seen as a potential successor to captain John Terry in the long-term.