Real Madrid boss Jose Mourinho ignored the media during Friday's press conference, which resulted in a walk-out by scores of journalists.
That did not go down well with the assembled journalists at Madrid's Valdebebas training ground and many took the decision to stage a walk-out as soon as Karanka arrived.
When Karanka did come out he was accompanied by Mourinho, but as soon as it was confirmed the Portuguese would not be answering any questions, it was estimated that more than 100 journalists and television crews from several different countries left the room.
Karanka then fielded questions from the journalists who stayed, but Mourinho remained silent.
Filippo Ricci, a journalist with Italian newspaper Gazzetta dello Sport who was among those who left, explained: "What happened was Mourinho decided not to come to the press conference, the usual press conference before the Clasico, and to send out Aitor Karanka.
"The press didn't like this decision and decided to quit the press centre as he was coming in.
"The surprise was that Mourinho also came into the press centre, but when the press officer said Mourinho wasn't getting any questions, at that moment around half to three-quarters of the press centre left."
Karanka said: "Whenever the coach speaks his words are blown out of proportion. He doesn't want that, nor does he want to be the one who heats things up before the match.
"He's preferred to stay quiet to avoid misunderstandings and it's not the first time I've spoken, it's a way of working.
"I've already been out (to speak to the media) 11 times, this isn't something unusual."
Asked if Mourinho not speaking to the media could be seen as a lack of respect to the Madrid fans, Karanka added: "We have the opinion of the fans in the Bernabeu and on the street. What the fans want is that Real Madrid are where they are now.
"They don't want a team that is knocked out of the cup by a Segunda Division B side, nor a team who continually fall at the last 16 of the Champions League.
"They want a coach who works 100% every day and is able to make the team fight for every title."
Tomorrow's clash is the first of four showdowns between Madrid and Barcelona in the space of 18 days.
Aside from this weekend's league encounter, which Barca go into holding an eight-point lead over second-placed Madrid with seven games remaining, the two Spanish superpowers also meet in the Copa del Rey final and in the two-legged Champions League semi-finals.