Born in
Copenhagen,
Frederiksberg Municipality, Manniche started his career with
Brønshøj Boldklub in 1977, signing for
Hvidovre IF three years later and helping it to the
Danish Cup in 1980 and the
Danish Championship in the following year; in August he made his debut with
Denmark, appearing as a second-half
substitute in a
friendly with
Nordic neighbours
Finland (2–1 win) – in total, he would win 11
caps in six years, but did not attend any major international tournament. In the middle of 1983, Manniche moved abroad, signing with defending
Primeira Liga champions
S.L. Benfica. In
his first season he helped the team retain the championship, scoring 11 goals in only 21 matches. Additionally, he netted twice in the 1985
Portuguese Cup final win against
FC Porto (3–1), winning another league trophy in 1987. Having played 132 official matches with 75 goals for Benfica, Manniche was affectionately known as "O Tosco" (
Portuguese slang for a person/player with few or no technical abilities). In the decades following his retirement he stayed firmly connected to the club, either watching games, mediating in business negotiations or supplying training equipment. In 1987, 28-year-old Manniche returned home, joining
Boldklubben 1903 – on 1 July 1992, it merged with
Kjøbenhavns Boldklub to become
F.C. Copenhagen. In its first year of existence, they won
the league; he played his last match on 17 April 1994, and became a coach for small Danish amateur sides. Manniche returned to Copenhagen in 1996, as an assistant manager. After a string of poor results he made a short comeback as a player, at the age of 37, calling it quits shortly after. The Portuguese footballer
Maniche was nicknamed in reference to Manniche. ==Honours==