JOHANNESBURG  When it comes to selecting just the right swear word to hurl at a referee, Wayne Rooney is a walking thesaurus. In exchanges with officials, he mixes and matches with such flourish, he might be confused for Roget’s bawdy cousin.

But if Rooney, a striker for England, lets fly a similar tirade on Saturday in his team’s first World Cup game, against the United States in Rustenberg, it is likely to be his farewell speech.

George Carlin had his seven dirty words, and FIFA, soccer’s international governing body, has its seven offenses. Any one of them will get a player immediately ejected from a game. Rooney might do well to read up on No. 6: “Using offensive, insulting or abusive language and/or gestures.”

On Saturday, the job of enforcing these rules for the match between England and the United States will fall to a squad of Brazilian referees who will need to keep their ears pricked for words they might not have learned in school. “We have to learn what kind of words the players say,” Altemir Hausmann, a referee’s assistant, told Globo TV Sports in Brazil. “All players swear and we know we will hear a few.”