Nagelsmann was born on 23 July 1987 in Landsberg am Lech, Bavaria. He played for FC Augsburg and 1860 Munich at youth level, and was the captain of Munich's U17 team. In the 2006–07 season, he was part of the second team but could not play a single match due to injuries. Nagelsmann returned to Augsburg for the 2007–08 season coached by Thomas Tuchel, but injured his knee and meniscus for the second time, damaging the cartilage. As a result, he decided to end his footballing career at the age of 20. He had already assisted his head coach Thomas Tuchel as a scout in the first half of 2008. He studied business administration in university for four semesters until he transferred to sports science. Then he focused on coaching, returning to his previous club 1860 Munich as an assistant to Alexander Schmidt for Munich's U17 team from 2008 to 2010.