Just 24 hours after John Stones headed to Manchester City, Everton have already signed his replacement, Welsh captain Ashley Williams.

Williams makes the move from Premier League rivals Swansea, although Williams' fee is set to be much less than theย ยฃ47.5m theย Toffees received for Stones.

The 31-year-old centre back has been at Swansea for the past eight seasons, but the Welshman admitted he needed a new challenge as he enters the twilight of his career.

โ€œFor me the new challenge was something I felt I needed, so I'm delighted to have joined Everton,โ€ Williams told Everton's website.

โ€œEverton is a great club with an unbelievable manager -- a world legend in football -- and I believe the club is going in the right direction.

โ€œThis is something I wanted to be a part of.

โ€œI look forward to seeing what the manager's plans are for me and the team. He's been one of the greatest centre-halves to ever play the game, so I look forward to learning from him and seeing what he can teach me.โ€

The man Williams is talking fondly about is of course Everton's new manager Ronlad Koeman, and the former Southampton boss said the signing of Williams exactly what they needed after Stones' departure.

โ€œWe wanted to bring in a strong player in the central-defence position, a player who knows the Premier League and Ashley fits the bill for us very well,โ€ Koeman said.

โ€œHe is an experienced defender and the kind of player we need in the team. He is a leader. He showed this at Swansea and he has shown it for his country and he is looking forward to his new challenge here at Everton.โ€