Germany did not lose to Spain because Thomas Muller didn't play.
Sure, his absence may have contributed to the outcome, but the Germans were chasing Spain all over the field. Maybe Muller would've finished the opportunity that Toni Kroos could not in the final minutes, but that's all conjecture.
What I do know, though, is that Muller should've played.
The 20-year-old striker was suspended for the semifinal after picking up a first-half yellow card in the quarterfinal against Argentina on an outrageous handball call. Because Muller had already picked up a yellow two games earlier against Ghana, he had to sit out.
The way the rule is written now, a player can pick up a yellow card in the first game and another three weeks later in the fifth game and have to sit out the semifinal. I know the rule exists to tone down aggressive tackling and mindless defending, but that situation seems a little harsh. After Muller scored four goals in the first five games of the World Cup, he had to sit and watch his team lose in the semifinal because he accidently hit the ball with his forearm in the first half of the previous game. Terrible.
To FIFA's credit, it did recently revise the rule to make it more fair. In the old version, cards were wiped out after the group stage and a new tally began in the Round of 16 and lasted through the semifinals. The new rule calls for the cards to be wiped clean after the quarterfinals to protect players from picking up one yellow card in the semifinals and having to sit out the final. (re: Michael Ballack in 2002).
I say, let's change it again.
I'd propose clearing players' records twice -- after the group stage and quarterfinals. This way, a suspension could only occur if a player shows a definitive pattern of rough play. The way the refs hand out yellows these days, even the most gentlemanly of scholars can get a couple of cards by accident. Between 1982 and 2006, the number of cards per game has risen every year but one (1998). In 2006, it was almost five per game, which is ridiculous.
Players shouldn't miss important games for petty fouls. Let's change the rule before a Michael Ballack incident happens again.