Real Madrid director general Jorge Valdano has leapt to the defense of under-fire coach Jose Mourinho.
The commission requested that the Spanish Football Federation take "appropriate disciplinary action" after the two coaches crossed swords in a war of words ahead of their meeting last weekend, with Mourinho claiming Preciado had "gifted" victory to Barcelona several weeks ago by fielding a weakened team.
Preciado told Mourinho he would have been "thrown in jail" in England for making such an accusation, branding him a "swine".
The commission said the comments "contributed to the creation of a hostile climate between the participants and supporters, especially in a match already deemed to be high risk".
But Valdano claimed the commission had made a "gross mistake" in their assessment of the situation.
"It is a gross mistake to put Mourinho and Preciado at the same level because of their statements," he said.
"One coach used solid arguments while the other used defamation. Both statements can't be regarded to be at the same level.
"Mourinho shouldn't stop being Mourinho. He was hired for his personality and he can express his feelings whenever he wants as long as he doesn't overstep his mark.
"We don't want to point fingers at who should be punished. This debate has been started again today and Preciado still has time to apologise for overstepping his mark.
"Just the other day, he said he had been unfortunate in the way he expressed himself. I now hope he does he same regarding his use of the word 'swine'."