FIFA changes rule on yellow card amnesties
Germany's Michael Ballack in 2002, Italy's Alessandro Costacurta in 1994 and Argentina's Claudio Caniggia in 1990 are the best-known players to have missed World Cup finals after picking up second yellow cards in semis.
So for this tournament, world football's governing body has shifted its usual amnesty for yellow cards from the end of the first round until after the quarter-finals instead.
That means players would only miss the final if they receive two yellow cards - or of course a straight red - in a semi-final game, rather than in the past when they may have carried one yellow card going into a semi.
"FIFA simply said we want to give the best players a chance to play in the final," spokesman Marius Schneider said.
"The discussion first came up when Ballack was ruled out."
England fans remember the old rule well because of Paul Gascoigne's tears during their semi-final in Italy in 1990.
Although they eventually lost to Germany, the always emotional Gascoigne wept on the pitch when he received a yellow card that would have ruled him out of the final.
Red card rules remain the same.
A red carries at least a one-match suspension and possibly more if the disciplinary committee considers the offence particularly serious. So, in theory, a player red-carded even before a semi-final could also miss the final.
Referees have generally been praised for their performances so far at this World Cup, although Germany were furious at Miroslav Klose's sending off against Serbia for a second bookable offence and the United States believe they were denied a legitimate third goal in their 2-2 draw with Slovenia.