Levante's Papakouli Diop levelled the accusations at Atletico supporters after his side's 2-0 win over the La Liga leaders on Sunday.
The midfielder became involved in a heated exchange visiting fans when he went to take a corner right at the end of the game.
Before the 28-year-old could take the set-piece, referee Jose Gonzalez blew the final whistle, leading to Diop kicking the ball into the away supporters.
Diop claims some Atletico fans then made monkey gestures towards him, and responded by dancing in front of them in celebration of Levante's victory.
On Monday, a statement from UEFA president MIchel Platini's office underlined its strong stance against any form of discriminatory behaviour.
"UEFA and its president Michel Platini strongly condemn all forms of discrimination including recent racist behaviour of fans in Spain," it said.
"UEFA has tough rules and sanctions against all forms of discrimination for all of its competitions.
"Where instances occur outside of our jurisdiction, we support appropriate action being taken by the relevant authorities."
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