Lehmann began his career with
VfB Stuttgart, and made one appearance for the
reserve team, on the last day of the 2007–08 season. He spent the next two seasons on loan with
Eintracht Frankfurt and then
Energie Cottbus, where he again played reserve team football, but he did make one appearance for the Cottbus first team in the
2. Bundesliga, as a substitute for
Gerhard Tremmel on the last day of the 2009–10 season, in a 4–1 win over
Rot-Weiss Ahlen. In 2010, Lehmann signed for
1. FC Heidenheim of the
3. Liga. In his first season, he served as backup to
Erol Sabanov, and made five appearances, but took over as first choice the following season. He lost his place to Sabanov again after 11 games of the 2012–13 season, and left the club in January 2013. After half a season without a club, he signed a one-year contract with
VfL Osnabrück on 2 September 2013, which was later extended until 2016. After four years with Osnabrück, Lehmann moved to
Regionalliga Südwest club
SV Elversberg on 2 August 2017. ==International career==