Barcelona defender Dani Alves has turned up the heat for their Champions League clash with Chelsea, claiming that the Blues play with "fear".

Alves believes that it the Londoners' unwillingness to attack, rather than the referee's decision not to award Chelsea numerous penalties, that cost that them a place in the 2009 tournament's final as the La Liga outfit went on to win the competition.

"People say Chelsea could have won but for the referee but that is not our problem. We do not control the referees. We are there to play football, to compete and to try to reach the final. What can we do about the referee?" Alves told The Guardian.

"Chelsea did not reach the final because of fear. The team that has got a man more, is playing at home and winning should have attacked us more. But of course, if you don't have that [attacking] concept of football that Barcelona have, you stay back and you get knocked out.

"You have to go forward. Stay back: losers. Go forward - winners. I think Chelsea lacked the courage to take a step forward and attack us. They paid for it."

The two sides meet in the Champions League semi-final on Wednesday at Stamford Bridge.