The German forward said that he was happy for his compatriots after they beat Argentina 1-0 in Sunday's final, but lamented his lack of participation.
Speaking to Fiorentina's official website, he said: "It hurts to not be there with them because I have been with them for seven years. But I still have time to win a World Cup or European Championship, so I want to play very well in the [Fiorentina] shirt over the next four years.
"The first aim is to play in Euro 2016. I am very happy for my country and my teammates, they were the best team."