Hartmann started his professional career with Hertha BSC, making his first appearance on 31 July 2008 in the 2008–09 UEFA Cup first qualifying round second leg against Nistru Otaci.
Hartmann | Lennart Ekdal | Lennart Åberg | Georg Hartmann | Franz Hartmann | Ernst Hartmann | The Big Picture with Thom Hartmann | Paul Hartmann | Otto Hartmann | Oliver Hartmann | Isobel Lennart | Hartmann Schedel | Felix von Hartmann | Erich Hartmann | William M. Hartmann | William Kenneth Hartmann | Thomas W. Hartmann | Thomas de Hartmann | Stephan Hartmann | Nicolai Hartmann | Lennart Poettering | Lennart Nilsson | Lennart Jähkel | Lennart Hyland | Lennart Hansson | Lennart Ekdahl | Lennart Carleson | Lennart Augustsson | Johannes Franz Hartmann | Heidi Hartmann |