ROSTOV-ON-DON, Russia — Mexico’s biggest worry at the World Cup may be its fans rather than its next opponent, struggling South Korea.

The Mexican football federation was fined 10,000 Swiss francs ($10,000) and warned of further sanctions over a chant by supporters considered to be homophobic during the opening game against Germany. Fans in Mexico use the chant to insult opposing goalkeepers as they take a goal kick. Widely considered a slur, some argue there is no discriminatory intent.

As traveling Mexican fans prepare to descend on this southern Russian city, players and the federation are imploring them not to repeat it at Saturday’s match, in messages on television and social media. The Group F game will be attended by South Korean President Moon Jae-in.

“For the Mexican fan, the World Cup is a party. You can see it on the street the whole time. But at the stadium, fans should stop the chant, or modify it, or change it all together. It would be better for everyone,” Mexican federation general secretary Guillermo Cantu said.

FIFA had warned the federation, he said, that supporters identified as chanting the slur could have their Fan IDs canceled.

“The rules have been there since the tournament started, so in the end, it’s our responsibility.”

THROUGH THE first round of games in the 2018 World Cup, the U.S. television audience has dropped about 44 percent compared with viewership for the last tournament in 2014, according to data from Nielsen.

The drop is consistent across the English-language broadcasts on Fox and the Spanish-language broadcasts on Telemundo. The games on Fox have averaged 1.98 million viewers, compared with 3.55 million on ESPN in 2014. Telemundo’s games have drawn an average audience of 1.87 million viewers compared with 3.3 million on Univision four years ago.

Together, the two networks paid more than $1 billion for the U.S. rights to this tournament and the 2022 event in Qatar, and now both face the same headwinds. The U.S. team, historically the strongest draw for domestic viewers, failed to qualify for the 2018 tournament. The time difference also means games start as early as 6 a.m. on the East Coast, earlier than the 2014 World Cup in Brazil. Both networks are newcomers to World Cup broadcasts.

A Fox spokeswoman didn’t respond to an email seeking comment. Earlier in the tournament, the company said that – relative to the average over the past four tournaments and excluding games played by the U.S. – early-stage viewership was up 32 percent.

THE INTERNATIONAL governing body for soccer has cleared U.S. referee Mark Geiger of wrongdoing, dismissing a Moroccan claim that the American asked for a Portuguese player’s jersey.

Morocco’s Nordin Amrabat made the accusation after a 1-0 defeat Wednesday at Luzhniki Stadium.

“FIFA unequivocally condemns the allegations supposedly made by a member of the Moroccan team,” a FIFA spokesman told The Washington Post on Thursday. “FIFA referees are under clear instructions with regard to their behavior and relationship with the teams and it can be confirmed that Mr. Geiger has acted in an exemplary and professional manner as an appointed match official.

“FIFA would like to remind teams of their duty to respect all principles” of sportsmanship.

The spokesman added: “Mr. Geiger strongly refutes these claims and categorically states that such a request was not made.”

World Cup referees are not made available to comment.

On Thursday, Geiger kept his assignment as the video assistant referee for Thursday’s Denmark-Australia match in Samara.

JOY AND DESPAIR are the closest of neighbors during the World Cup as emotions swing on every shot. The tension is so high it’s cruel when bad luck rears up, and own goals are one way that can happen.

If the number of own goals are any indication, this World Cup is already among the cruelest in history. There were five own goals through the first 20 group-stage games, 11 percent of the total goals scored.

The record for own goals in a World Cup was set in 1998, when six were netted out of a total of 171. That amounts to 3.5 percent of the goals scored that year, the highest rate in World Cup history.