Zenden joined newly crowned UEFA Champions League champions Liverpool on 4 July 2005. He started his Liverpool career being used regularly as a left midfielder, and was in the starting line-up as Liverpool won the 2005 UEFA Super Cup. However, he suffered a serious cruciate ligament injury in his right knee in December 2005, which ruled him out for the rest of the season. He recovered for the start of the 2006–07 season and was part of the Liverpool team that won the 2006 FA Community Shield. After the departure of German central midfielder Dietmar Hamann in the summer of 2006, Liverpool manager Rafael Benítez indicated that he saw Zenden as an option in the central midfield.