Alvaro Morata scored against former club Real Madrid in Thursday's derby before performing an unusual goal celebration.
Morata placed his right hand over his left shoulder and onto the letters on the back of his jersey.
At first glance this just looked like Morata was pointing to his name but there was more to the story.
Morata, who played for Real 95 times in two spells between 2010 and 2017, had been verbally abused by fans before kick-off on Thursday.
Groups of Real supporters chanted "rata", meaning rat, at Morata.
His celebration was an attempt to respond to those fans by temporarily making his jersey match their insult.
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