FC Admira Wacker Mödling
Born in Lilienfeld, Lower Austria, Lienhart joined SK Rapid Wien's youth setup in 2008, aged 12. He made his senior debut for their reserve team on 16 April 2013, coming on as a late substitute in a 3–3 away draw against FC Admira Wacker Mödling Amateure for the Regionalliga championship.