Gabino Sánchez Llamazares, author of 'Hogar fútbol', said he wrote the book because he believes there is a degree of racism and xenophobia in both society and sport.
He said many admired athletes have suffered discrimination, and that telling their stories could help people empathise with those who face discrimination but are not famous.
Gabino Sánchez Llamazares said: "Our players have a name, but the rivals are 'the black one' or 'the Moor'."
Asked whether hate in sport is resurging, he said he partly shares that view: those who express it remain a minority, but they now shout or are heard more, on social networks and in society.
He added that people are less racist than hypocritical, saying many who insult later want a photo with Lamine, Nico Williams or Vinicius.
Sánchez Llamazares said sport has always been part of his life: he played handball, football and athletics, and now follows it as a fan, describing it as health, companionship and fun.