Born in
Rødovre, Rieper started his career at Danish club
AGF in 1988. While at AGF, he debuted for the Danish national team in the 1–0
friendly match win against
Sweden on 5 September 1990. He played a further three national team matches before moving on to
Danish Superliga rivals
Brøndby IF in 1992. While at Brøndby, he secured a place in the national team starting line-up and played 38 matches in a row from October 1992 to August 1996. Rieper won the 1994
Danish Cup trophy with Brøndby before moving abroad in December that year to play for English Premiership club
West Ham United, signing initially on loan before a £1 million fee at the end of the season made the transfer permanent. In 1997, he moved to Scotland to play for
Celtic, with whom he won the
Scottish league championship in
1997–98. Rieper suffered a toe injury in October 1998 which he never fully recovered from. He did not make another professional appearance and announced his retirement in July 2000. ==International career==