Former Germany striker Miroslav Klose said he had been surprised by how quick football has become since he retired as an international player.
Klose, Germany's record goal scorer, officially ended his playing career earlier this month while accepting an invitation to work with the national team as he studies for his coaching badges.
He was given a first insight of what he can expect when he joined coach Joachim Low and his squad this week ahead of Friday's World Cup qualifier against San Marino.
"I've always been following football games, but when you are out here on the training field you see even more how much the quality and the pace has increased since my time as a player,'' the 38-year-old told a news conference.
"I am happy to have been given this possibility. I thought about it for a long time and decided to see the other side for a change.
"The opportunity to work with a World Cup-winning coach is not something many people get.
"I just want to soak it all up and take it with me for my further development. I was integrated right from the first meeting and it's all a huge honour."
Klose scored 71 goals for Germany, ending his international career with victory in the 2014 World Cup final.
He had been without a club after leaving Lazio in the summer and also played for FC Homberg, Kaiserslautern, Werder Bremen and Bayern Munich.