Real Madrid boss Jose Mourinho claims he has learned a sporting lesson from Barcelona and is not going to talk about referees ahead of Tuesday's Copa del Rey semi-final second leg at the Camp Nou.
Mourinho spoke to the Spanish media after training in Madrid on Monday, soon after Barcelona's stand-in coach Jordi Roura had questioned the "permissive" refereeing style of Alberto Undiano Mallenco in an apparent attempt to ensure a strict line was taken with any physical play.
The Portuguese said he had nothing to say about the officials because he had learned from the Catalan club that it was not proper to speak about referees or to try and influence them in any way.
"I prefer to stick to the lessons we have received in the past from Barcelona," he said. "Lessons of sportsmanship, of how to act in football.
"I do not speak about referees, nor crowd around them, nor look for yellow cards for opponents, nor conceal things. And, of course, lessons in how to play football, which they do very well. We must try, humbly, to follow that line."
Tuesday's game – the first leg of which ended in a 1-1 draw at the Bernabeu – begins what looks likely to be a season-defining three games in eight days for Madrid.
They face Barcelona in La Liga at the Bernabeu on Saturday and then take on Manchester United in the Champions League at Old Trafford on March 5.
Mourinho said both he and his players, whose struggles against supposedly smaller teams have seen them drop 16 points behind Barcelona in La Liga, enjoyed it when the pressure was on.
"These are the games that we like to play, me just as much as the players," he said. "I prefer games of this size, with this pressure.
"We want the games to come quickly - in the Copa, in La Liga and in the Champions League."
Neither Madrid's recent good record at the Camp Nou, which includes the 2-1 win which clinched last season's La Liga title, nor Barcelona's recent apparent dip in form, would have any bearing on the latest clasico, the coach said.
"This is an isolated game, with nothing to do with past ones," he added. "Anyway, that was a long time ago. We have not played there for months.
"We must try and play as well as possible to get the best result possible. Form does not matter so much in games between the best teams. The moment in which the game is played has no significance."
Madrid fans had positive news from training, with Xabi Alonso and Karim Benzema - both of whom missed Saturday's 2-1 Primera Division comeback win at Deportivo la Coruna through injury - back in harness.
Mourinho said he had not yet decided who would start on Tuesday, but added: "Every player wants to play tomorrow. I like matches like this. Benzema trained with the team yesterday and today as well. I think [Alonso] is ready to play."
Kaka, whose contribution to the comeback at Deportivo included a sweetly-struck 20-yard equaliser and the pass that led to Gonzalo Higuain's late winner, may or may not have a role to play at the Camp Nou, the coach added.
"I do not know," he said. "It is not that I do not want to say, it is that I do not know. I have not thought about it yet. Normally I know and I do not say. This time I do not know."