Born in Saarbrücken,[2] Herrmann began playing football at FC Uchtelfangen based in nearby Illingen.

[3] On 16 January 2010, Herrmann made his first team debut, appearing as a substitute in a Bundesliga match against VfL Bochum.

Gladbach scored less than a minute later, with Herrmann providing the assist for fellow debutant Fabian Bäcker, but went on to lose the match 2–1.

[9] On 24 March 2013 he was called up for the senior national team for the first time, for a 2014 World Cup qualifier against Kazakhstan.

[10] Herrmann made his debut on 10 June 2015 at the RheinEnergieStadion in Cologne, starting the match and assisting Mario Götze's opener in an eventual 1–2 friendly defeat to the United States.