Ashley Williams has made 34 Premier League appearances this season. GLYN KIRK/AFP/Getty Images

Everton are planning a move for Swansea City defender Ashley Williams to solve their defensive problems, a source close to the player has told ESPN FC.

Everton have the sixth worst defensive record in the Premier League this season and the two first-half goals they conceded in Wednesday's 4-0 Merseyside derby defeat to Liverpool were the 12th and 13th headed goals they have let in this season -- more than any other club in the Premier League.

Toffees boss Roberto Martinez, who is under pressure at Goodison Park, is keen to resolve the recurring defensive issues that are troubling his side next season, and has identified Williams as his top target.