Daniel Agger
Daniel Agger is wanted by Barcelona as they attempt to sign a new expereinced centre-back. [Reuters]

Barcelona are plotting a summer raid on the Premier League as they look to convince Liverpool defender Daniel Agger and Chelsea star Juan Mata to make the move to the Camp Nou.

Despite winning the La Liga title it is believed that manager Tito Vilanova is keen to further strengthen his squad after the lacklustre performance in the Champions League that saw them lose 7-0 to Bayern Munich over the two legs.

Spanish publication Sport believe that one of Vilanova's priorities is to sign a new centre back as there is little cover behind Gerard Pique and the aging Carles Puyol. Paris Saint-Germain defender Thiago Silva had been mentioned but it is believed that Agger is now the front runner.

The Liverpool defender would be a far cheaper option than Silva who cost PSG close to £40m last summer. Agger is also believed to fit the Barcelona model as a defender who is comfortable bringing the ball out of defence, whilst also having a commanding physical presence.

Agger was linked with a move away from Liverpool last summer but he always stated that he would remain loyal to Liverpool. However, after another disappointing season the chance to join the Spanish champions may well be hard to refuse.

The Dane is contracted until the summer of 2016 so Liverpool would still be able to demand a sizeable fee for a player who has long been one of the most consistent performers for the club.

Juan Mata
Cheslea's Juan Mata is another target for Barcelona this summer. [Reuters]

While Barcelona are determined to strengthen their defence it seems they are also keen to on luring Chelsea's player of the season Mata back to Spain.

The Mirror reports that Barcelona are aware of rumours circulating that new Chelsea boss Jose Mourinho is willing to listen to offers for the midfielder. While this would seem a strange move from the former Real Madrid manager, speculation is increasing over the future of Spain international.

A report states that Barcelona will bid £30m for the 25 year old, which is just £7m more than Chelsea paid for Mata back in 2011 when he signed from Valencia.

Mata has never suggested that he is unhappy at the London club but he has been forced to comment on his future while out in Brazil where he is representing Spain in the Confederations Cup.

"Nobody at Chelsea has told me that Mourinho wants me out," Mata told Marca. "When I finished the season I was told that they were very happy with my performances and with the two years I've spent with the club.

"I have three years left on my contract. I'm very happy with Chelsea. Mourinho? I'd prefer to wait until I meet him and work with him before I judge him. That's simple logic."