In 2000, Miller moved to Bundesliga side VfB Stuttgart, although he generally played for their reserve squad in the third-division Regionalliga Süd, where he made a total of 44 appearances for the team over the following two seasons.

However, he became the club's first-choice goalkeeper for the 2004–05 season and made his professional debut on 7 August 2004 in KSC's 1–1 home draw to Wacker Burghausen in the 2.

Miller is often compared to KSC's goalkeeping legend Oliver Kahn, who played for the club from his childhood until the 1994 transfer to Bayern Munich, but does not feel comfortable with the comparison.

Bundesliga, where he amazingly saved several close-range shots in the second half and helped KSC to drive home one point as the match ended in a 1–1 draw.

On 6 May 2010, he confirmed that would leave Karlsruher SC after seven years at end of the season, and on 2 June 2010, he signed a two-year contract for Hannover 96.