Roberto Martinez has insisted that John Stones will not be for sale at any price in the January transfer window.
The Everton centre-half was the subject of repeated bids from Chelsea over the summer and recent reports have suggested that the Blues will try again with an offer of £45m next month.
"It doesn't matter if a club comes in. We created a squad during the summer to see how far we could go over the season," Martinez is quoted as saying by The Sun.
"We'll never lose anyone in January, unless it's somebody who hasn't been playing and we need to find a solution. If he's a top performer, it's not even a consideration."
Currently on a six-game unbeaten run, the Toffees next welcome table-toppers Leicester City to Goodison on Saturday afternoon.