Sevilla attacker Lucas Ocampos was calm after an incident during victory at Rayo Vallecano last night.
A fan was filmed touching Ocampos' backside as he prepared to take a throw.
"The images were seen," he later said.
"I hope that LaLiga takes it seriously, as it takes racism and other things. There is always a fool, not all fans are like that. If it happens in women's football we know what can happen.
"I restrained myself because I have two daughters. Let a fool not stain all fans that have always behaved very well."
Regarding the victory against Rayo, he added: "A super demanding, super complicated match, on an always difficult court. Happy with the victory, they are three points that we needed a lot."