Germany's players attend a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's goalkeeper Manuel Neuer attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's Mats Hummels signs for fans after a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Chen Cheng)

Germany's players attend a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's Niklas Suele (R) attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Chen Cheng)

Germany's Antonio Ruediger attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Chen Cheng)

Germany's goalkeeper Marc-Andre ter Stegen (L) attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's Thomas Mueller (R) attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's players attend a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)

Germany's Thomas Mueller attends a training session ahead of the 2018 Russia World Cup in Moscow, Russia, on June 13, 2018. (Xinhua/Liu Dawei)