Real Madrid coach Carlo Ancelotti said on Saturday that Barcelona's complaints over his club allegedly influencing LaLiga referees were unprofessional.
Barcelona president Joan Laporta and coach Xavi Hernandez complained on Friday about Real Madrid's television channel broadcasting videos which criticised match officials.
Xavi said LaLiga was "completely adulterated" because of the influence leaders Madrid supposedly exert on referees.
"I'm a professional and as such, I will not lower myself to that level, out of respect for Spanish football," Ancelotti told a news conference.
"Don't ask more about that because I don't want to lower myself (to that), it's unprofessional."
Real Madrid are 10 points clear of Barcelona, fourth, and city rivals Atletico Madrid, third, who visit the Santiago Bernabeu on Sunday.
Ancelotti may have to use a player out of position at centre-back for the derby clash if Antonio Rudiger does not recover from a knock.
With Eder Militao and David Alaba injured, Nacho Fernandez is currently Madrid's only fit central defender.
Midfielder Aurelien Tchouameni has played there in the past for Madrid but he is suspended.
"Rudiger has improved a lot ... we'll look at him tomorrow and take a decision," said Ancelotti.
The coach said Dani Carvajal, Ferland Mendy and midfielder Eduardo Camavinga are his options if Rudiger is not fit.
"Camavinga has never played there but has the characteristics to," added Ancelotti.
"He's fast and strong in duels, they are the three options and I'm confident in all of them."