Guardiola upset by Chelsea tactics

Like Chelsea, Barcelona finished the semi-final first-leg with two yellow cards - Alex, Michael Ballack, Yaya Toure and Carles Puyol all going into the book - but Chelsea committed more than twice as many fouls and Guardiola believes the visitors should be punished for playing a negative game.

"Chelsea were constantly interrupting play with fouls while we played our normal attacking game," he said. "One team is playing an attacking game and that should be taken into account."

"The players complained about the referee, they were upset about that," he revealed after the match. "I don't complain about the referees, but I think the referee should see which team is attacking and which team is interrupting the play.

"We play clean; we foul as little as possible. And we have the same amount of cards as them. It's not normal, it's not fair.

"We said before the game: 'no hard tackles, no fouls, it's not necessary', but we attacked, attacked and attacked and it's ridiculous that we should end up with the same amount of cards as them."

Guardiola believes such decisions could decide games in elite European competition.

"In the Champions League, small details decide games and could be the difference between winning or losing the tournament," he said.

Nevertheless, Guardiola said he was not unhappy with the result.

"The result is what it is. Chelsea played very defensively, they were very disciplined and very strong with six players defending," he said. "We will go to London and to the Bernabeu (for Saturday's Primera Division game against Real Madrid) with the same spirit."