Answer
Metzelder's professional career was one full decade, beginning in 1999 when he joined Borussia Dortmund and ending in 2009 when he retired from professional football. During his career, Metzelder played for Borussia Dortmund, Real Madrid, Schalke 04, and Hannover 96. He also represented Germany at the international level, appearing in two World Cups and two European Championships.