Chelsea have completed the signing of Bolton Wanderers defender Gary Cahill. The fee is reported to be initially £7m.

The England international, 26, told his new club’s official website: “Chelsea is a massive club, it is a club that looks to win trophies season in season out and it is a big opportunity for me to be a part of that. Opportunities like this you can’t turn down.”

Wigan Athletic have taken Chelsea left-back Patrick Van Aanholt on loan for the coming season.

The 21-year-old Dutchman has previously had loan spells with Coventry City, Newcastle United and most recently, Leicester City.

Wigan manager Roberto Martinez told his club’s official website: “Patrick is a player with enormous potential. Technically he is very gifted, very comfortable in possession and physically, he uses his intensity to defend very effectively.

“He can play left back or left wing back position and without a doubt he’s got a phenomenal career ahead of him and I hope he can settle in Wigan really quickly and start enjoying his football as a Latics player.

“We rate Patrick really highly and his professionalism and his personal attributes will be a huge asset to us this season.

“Like Tom Cleverley last year, he is a young player who is hungry to learn his trade and I feel both parties can benefit hugely from the move. We are delighted to welcome him on board.”

Bolton Wanderers have taken Chelsea winger Gael Kakuta on loan for the next six months.

The 20-year-old Frenchman spent the latter half of the season on loan with Fulham last season.

Bolton manager Owen Coyle told his club’s official website: “I’m delighted that Chelsea have enabled us to take Gael on loan and I’d like to thank [Chelsea manager] Andre [Villas-Boas] and the club for that.

“He is someone whose progress we have tracked since he first broke into the Chelsea first team a couple of years ago. He is skilful, quick, exciting to watch and I’m really looking forward to working with him.”

Chelsea have signed Valencia winger Juan Mata for a reported fee of over £20m.

The 23-year-old Spanish international has put pen to paper on a five-year contract at Stamford Bridge.

Mata told his new club’s official website: “Right from the first moment there have been good feelings all around me. Training has been great and the players are a great group to train with.

“Valencia was a big club anyway but I have left to join a bigger club and it is all about the opportunity to win trophies and I have that here.”

He added: “He [Chelsea manager, Andre Villas-Boas] said he wanted Chelsea this season to play more attacking football, and that I would be a big part of that. Villas-Boas is someone who won almost everything last year and we are both here with the idea of winning lots this season.

“The plan is that I can play on either flank or even in the middle playing in between the lines of midfield and attack. I like to keep the ball and use it well, I am an attacking player and above all I like to set up goals and score them also.

“I want to adapt as quickly as possible to my new surroundings, my colleagues and this league, and I would love to win a trophy in my first season. If it can be the Premier League then great.”