A blue streak will get players yellow or red
But swearing a blue streak isn't the only thing that could lead a referee to toss a player from the World Cup. Obscene gestures and overly aggressive behavior are big no-nos, too, and the refs will be on the lookout.
On Monday, England's Wayne Rooney was given a yellow card after referee Jeff Selogilwe claimed the striker swore at him during an exhibition game against a South African club team.
"Wayne himself just has to make sure he controls his frustrations in the right manner - and takes it out on the opposition and not the referees," said England's captain, Steven Gerrard, on Thursday.
Referees can't give out cards for what they think was said, and FIFA requires World Cup referees and assistants to be proficient only in English.
"At the end of the day, you don't understand half of it," former Premier League and FIFA referee Graham Barber said. "So what do you do about it? Say 'I think he swore at me, so I sent him off?' "
If it's said in the referee's native language or English, however, get ready to see yellow.
FIFA denied reports that match officials have been given lists of swear words. But one member of Saturday's officiating crew said they're boning up on English and American curses. Carlos Simon will referee Saturday's match in Rustenburg, assisted by Roberto Braatz and Altemir Hausmann.
Blanco ready to go. Mexico forward Cuauhtemoc Blanco, the oldest field player at the World Cup at 37, no longer has the speed he once used to leave defenders behind. Nevertheless, he will try to help his country get past the quarterfinals, the farthest the team has reached at a World Cup.
Blanco wrote to his fans on his website that "I'm going for you" and that all the hard work Mexico has put in before the tournament will be reflected Friday in the opening match against South Africa at Johannesburg's Soccer City.
There are only four players older than Blanco at the World Cup, all goalkeepers.
The striker, who has been without a club since playing for Mexican second division Veracruz last season, will be playing in his third World Cup after being part of the 1998 and 2002 tournaments.
Blanco, who was not chosen for the 2006 World Cup in Germany, has also played for the MLS Chicago Fire, where it appeared his career would end. But he came out of a five-month retirement and was recalled to the national team after good performances in the United States.