The Referees' Committee will name the official for Saturday's clash between Real Madrid and Barcelona on Tuesday.
Appointments for fixtures in Spain's top flight are usually made two weeks in advance, according to AS, but the decision to delay naming the referee has been made to ease the pressure on the individual in the build-up to El Clasico.
It is understood that a statement will be made at 9pm local Spanish time on Tuesday, where the referee will be revealed.
Barcelona will enter the first Clasico of the season three points clear of Real Madrid at the top of the La Liga table.
Lionel Messi has been tipped to return to the fold for Barcelona at the weekend having been out of action since September with a knee problem.
