The Brazil star was upset by the abuse Dani Alves received during Barcelona's victory over Villarreal.
The Brazilian fullback dealt with the incident in good humor, picking up the banana and eating it, but his compatriot took to Instagram to voice his disgust at the abuse.
"We are all equal, we are all monkeys, say no to racism," he wrote on the social media site, accompanied with the hashtag #weareallmonkeys.
"It's a shame that there's such prejudice in 2014. It's time for people to raise their voices. My way of expressing my support is to do what Dani Alves did. If you think so too, take a picture of yourself eating a banana and we will use what they have against us to our advantage."