Christoph Kramer took a nasty bump in the World Cup final. He certainly looked like he was out of it, and the ref appears to confirm those suspicious:
He told Gazzetta dello Sport: “Shortly after he’d been struck by Garay, Kramer came to me, asking ‘ref, is this the final?’
"I thought he was joking so I asked him to repeat the question, and he said: ‘I need to know if this is really the final.’
"After I said ‘yes’, he was a bit stunned and said: ‘Thanks, that’s important to know.’
"I informed [Bastian] Schweinsteiger and they replaced Kramer."