Herr started his career at local club FC Basel in 1984 where he was a squad player and played mainly for the FC Basel Under-21's for the first couple of seasons. He broke into the first-team during the 1986/87 season, playing 31 games over the course of the entire campaign. Basel failed to avoid relegation to the Nationalliga B in 1988 and Herr left to join Lausanne Sports who continued to play in the Nationalliga A. His first season at Stade Olympique de la Pontaise saw him achieve some excellent form and he was called up to the Swiss national team. In Summer 1992, he signed for Swiss champions FC Sion where he won the Swiss Cup twice, in 1995 and 1996. Injury forced him into retirement in 1996, aged just 30.