Rayo Majadahonda were losing 2-1 when Sarr left the pitch in the 83rd minute.
“An ultra in the stands came down and started insulting me,” he explained.
“If it was a youngster – a child at best – maybe I could understand, but here it was, an old man throwing insults.
“As a player who comes to Europe to play, who tries to feed his family back in Africa, it’s just very hurtful.”
Sarr hoped his actions would expose the perpetrator to a wider audience and highlight the racism.
“I didn’t want to be aggressive or violent,” he said.
“I just wanted to find him because I wanted the video to go around [and] be viral on social media, so people could see what is happening.”
The RFEF judged Sarr’s reaction to be “contrary to good sporting order” but said there were “mitigating circumstances” when deciding on the length of his ban because of “justified sufficient provocation, motivated by the racist insults received”.
Sestao were ordered to play two home games behind closed doors and were fined 6,001 euros ($6,440, £5,140) for “failing to act diligently or co-operate in the repression of violent, racist, xenophobic or intolerant behaviour”.
Sarr says he has previously experienced racism playing in Spain but this abuse was on a different level.
“Two years ago, a fan in the stand was making gestures but at the time it made me laugh.
“This time I just couldn’t cope with it because it was just pure racism. It’s the first time in my life I can really say I’ve been the victim.”
