Mexico City: Mexican football got a boost in September when former Brazil and Barcelona star Ronaldinho -- a two-time FIFA player of the year -- joined modest local club Queretaro.
The upbeat mood didn't last long. Even before he had played his first match, he was the subject of a racist attack -- the kind that has become common for black soccer players across Europe.
Mexico has a history of racism on the pitch. But it was largely overlooked until the arrival of Ronaldinho.
Racism in Europe often involves white against black. But in Mexico and other parts of Latin America that have mixed-race societies, it can involve dark-skinned people shouting insults at other dark-skinned people.
Carlos Trevino, a former official of the Queretaro state government, launched an attack on Ronaldinho on his Facebook page before the Brazilian had played a single game. He had only just arrived in town, causing minor pandemonium, when Trevino exploded.
"Seriously, I try to be tolerant, but I hate football and the idiotic phenomenon it produces," Trevino wrote. "I hate it even more because people flood the streets, meaning it took me forever to get home. And all this to see an ape; a Brazilian, but an ape just the same."
Following a wave of criticism, Trevino apologized to the club and player. But he received no punishment, which typifies how Mexican football officials have dealt with the growing problem.
Decio de Maria, president of Liga MX -- Mexico's top league -- suggests racism is not a problem; just misunderstood.
"Mexico is not a racist country," he said. "This is a country where we use nicknames. On the streets, they single people out. There are profanities that, when they are said, do not mean what they literally mean. Calling someone by a nickname is not discrimination. Those who cross the line should be taken to court," said de Maria.
Valeria Berumen, a high-ranking official of a Mexican government office that works to combat racism, says, "there are two engines that push discrimination. One is football. The other is the Internet. They have the ability to spread positive messages, but they also can spread discrimination, racism and xenophobia."
Just after the Ronaldinho incident, Colombian player Dorlan Pabon of the Monterrey club heard fans calling him an "ape" in a match in the central city of Leon. The club said it would investigate. By the end of October, the club had not announced the results of its investigation.
The list of recent racist incidents in Mexico is growing.
In February, fans of Pumas in Mexico City chanted monkey noises whenever opposing Colombian players Eisner Loboa and Franco Arizala touched the ball.
Last year, Ecuadoran Christian Benitez complained about being the target of monkey chants in a match in Mexico City. He was playing at the time for America, another top club. Benitez died of a heart attack a few months later after signing for Qatari club El Jaish.
Football racism is a nasty problem outside Mexico, too.
Brazilian club Gremio was kicked out of the Brazilian Cup earlier this year after its fans racially abused an opposing player.
In a match this year at Spain's Villarreal, Barcelona's Brazilian defender Dani Alves had a banana thrown at him. Alves, who is black, picked it up, bit off a piece and then discarded it before taking his kick.
Earlier this year the Mexican league adopted rules set by football's governing body FIFA. They allow the referee to stop the match if racist incidents take place. If they continue, he can take the teams off the field for 10 minutes. And if they persist, he can suspend the match.
So far, no Mexican referee has acted under any of these rules.
Daniel Luduena, an Argentine midfielder playing for Pumas, said the problem was worse at some stadiums than others.
"There's not racism on all the fields in Mexico,' he said." The problem is, perhaps, at three or four stadiums. But there is no reason to wait for an extreme case before acting to stop it."