Ecuadorian Guerrón was subject to racist abuse from a section of the Sporting fanbase, much to Celestini's disgust.
"Guerrón didn't know that they were for him," began the Swiss midfielder.
"I imagine that it doesn't happen in his country, so if nobody says anything he's not going to know.
"Clearly he heard things, but these things happen. You can't throw out 1,000 people... you can't do anything.
"Guerrón maintained a perfect attitude throughout the match. He did nothing wrong: all he did was come to play in a game of football. But because he is of a different colour, some of the fans goaded him. There's no easy solution to that.
"In society, we have lots of unresolved matters. Thus to throw out 500 is just nonsense."
Orderly
Moving on to football matters, the former Marseille man focused on the differences between ex-manager Michael Laudrup and current boss Víctor Muñoz.
"Bernd Schuster and Laudrup gambled on a more spectacular game, while Muñoz wants more order," he said.
"There are different ways of running a team, but none is better and none is worse. This year there's probably a more orderly defence, and more freedom in attack.
"At the back everyone knows very well what they need to do. Clearly there's a big change there when compared with other seasons.
"This is the most orderly Geta side since Schuster's. The other coaches gave us more freedom in other ways, which has good and bad aspects.
"This year the boss has gone for a more tactical and orderly approach, but that doesn't necessarily mean it's more defensive. You just adapt."
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