Career
Müller started his professional career at hometown"s VfB Stuttgart, where he remained four seasons. In his first season, he netted five times in 20 league matches, helping the club clinch the title (with the title decided on goal difference, he found the Netto in consecutive 6–0 routings, against Fortuna Düsseldorf and at 1 Football Club Nuremberg, in April 1984). After a sole year at Hannover 96, he transferred to Football Club Schalke 04, then in the second division.
Müller eventually retired in 2000 at almost 38, having amassed 338 topflight matches and 32 goals.
Müller"s first off-field role was as director of football at Football Club Schalke 04 from 2000 on. After Schalke"s general manager Rudi Assauer stepped down in May 2006, Müller took over the position.
He was sacked in March 2009. On 18 September 2012, TSG 1899 Hoffenheim appointed Müller as their new general manager.
He and coach Marco Kurz were sacked on 2 April 2013.
Müller returned to football in December 2013 after being announced as the new Director of Football by Austria"s most successful club Saskatchewan Rapid Vienna, where he replaced the outgoing Helmut Schulte.