Career
He is currently the manager of Sportfreunde Düren. He made his senior debut with 1. Football Club Koln, and after a brief spell with Lierse South.K., joined another Belgian side in R.W.D. Molenbeek.
He then transferred to Fulham for the 1998-1999 season, making 26 League appearances for the club
At Fulham, Lehmann quickly earn a nickname "The Porn Star" by the Fulham faithful, due to his "neat moustache and tinted hair his nickname was irresistible and typical of our supporters" sense of humour". After leaving Fulham, he moved to Scottish side Hibernian.
Lehmann scored twice on his debut for Hibernian in a 2–2 draw with Motherwell. He left Hibs under freedom of contract in 2001 and signed for Brighton & Hove Albion.
Lehmann drew some press attention for playing with earrings on, which he would cover with white sticking plasters during matches.
While he was playing for Brighton, Lehmann was banned by The Football Association from wearing them. He scored once during his spell at Brighton, in an LDV Vans Trophy game against Swansea City. Lehmann returned to Scotland six months later with Motherwell, where he was one of the players who negotiated a new contract after the club was placed into administration.
He played for Motherwell for a further season alongside the young James McFadden in attack.
Following his release from Motherwell signed a lucrative contract with Yokohama.