Barcelona's Dani Alves, who is black, was about to take a corner kick during Sunday's 3-2 win at Villarreal when a banana was thrown at him. The Brazilian star picked it up, peeled it and ate some of it before throwing the rest aside.
The 30-year-old says black players have suffered through racism in Spain for years, adding that humor is the best way to combat racism in sports.
Barcelona expressed its "complete support and solidarity" with Alves. Besides teammate Neymar, Argentina striker Sergio Aguero, Brazil women's striker Marta and former Brazil international Roberto Carlos posted Internet photos of themselves with bananas.
Alves has previously called for drastic measures to be taken to tackle racism in Spanish soccer after being subjected to racial chants.
(The Associated Press contributed to this report)