 Lambertz began his youth football career in 1990 with SG Orken/Noithausen.He also played for Bayer Dormagen, TSV Norf, Borussia Mönchengladbach and VfR Neuss prior to joining Fortuna Düsseldorf.Lambertz began his professional career at Fortuna Düsseldorf which was playing in the Oberliga Nordrhein at the time.