Real Madrid coach Jose Mourinho criticized Pep Guardiola, his opposite counterpart at FC Barcelona for talking about referees on Tuesday.

Speaking in his pre-game press conference, ahead of the first leg of the Champions League semifinal between Real Madrid and Barca, Mourinho made reference to Guardiola's comments last Saturday night in which he ironically mentioned the decision to rule out a Pedro Rodriguez goal for offside during the second half of the final of the Copa del Rey last week.

Rodriguez was offside by a question of inches and the Barcelona coach dealt ironically with the decision when asked about the chance of a Portuguese referee Pedro Proenca being designated to officiate Wednesday's meeting between the sides. The Barcelona camp were clearly unhappy at a fellow countryman of Mourinho's being in charge of what is likely to be a highly charged affair, although finally German referee Wolfgang Stark has been designated to take change of the match.

"Guardiola has done something I have never seen before, criticize a correct decision," said Mourinho in his press conference.

"More important than the referee is the pressure that has been exerted for it not to be Proenca. We have seen the start of a new era. In the past there were two groups of coaches: one small group that never talked about referees and a larger group, in which I am included, which talked about them when they made important mistakes. Now there is a third group in which Guardiola is the only member, who criticize the referee for a correct decision. I have never seen that before."

"In his first season he lived the scandal in Stamford Bridge ( when Chelsea had four penalty appeals turned down against Barcelona). On other occasions we have had to play with 10 men and this year they were in trouble against Arsenal and everyone knows what happened (Robin Van Persie was sent off). And now he criticizes a linesman for a correct decision," said Mourinho.

"I hope the players help stark and that he is a good referee. I hope he has quality and the fortune to get things right," he added.