Everton sign a center back, exit door opening for John Stones?

Everton Football Club announced the signing of center back Mason Holgate from Barnsley on Wednesday. The 18-year-old completed the move to Merseyside for an undisclosed fee and will add to the club's back line depth.

The obvious question now from a Chelsea perspective is: Does this open the door for a John Stones transfer?

Chelsea have had several bids for Stones rejected and Toffees manager Roberto Martinez has been adamant the last few days about keeping the talented English defender.

Everton boss Roberto Martinez on John Stones. "The player is not for sale and that’s the end of it." #EFC #CFC

— Pete O'Rourke (@SportsPeteO) August 13, 2015

Martinez backed up his statement today in his weekly press conference with a more subtle approach to the rumors.

"For a young man to show that leadership just shows where he's at a footballer and why we value him so much. We are looking forward to see the best of John over the next few seasons not just the next few weeks."

Roberto Martinez; Source: Liverpool Echo

Despite the repeated denials from Everton's side, no deal is ever dead until the transfer window completely shuts. They are clearly trying to add as much depth as possible in case they lose a player. Expect this saga to drag on all the way until September 1st.