 He and Vejle won the 1984 Danish championship trophy, and he scored his only international goal, in a 1986 World Cup qualification game against the Republic of Ireland in November 1985.In the winter 1985, Sivebæk moved to England to play for Manchester United, joining fellow Dane Jesper Olsen.He scored one goal in his time at Manchester United, namely the first Manchester United goal under newly hired manager Alex Ferguson in November 1986.