A powerful and uncompromising defender, Nielsen was a key component of the dominant PSV side that lifted the European Cup in 1988.
| 1975–1979 | Fremad Amager |
| 1979–1986 | Feyenoord Rotterdam |
| 1986–1990 | PSV Eindhoven |
| 1990–1991 | Fremad Amager |
| 1991–1992 | Boldklubben 1903 |
| 1992–1993 | F.C. Copenhagen |
| 1993–1994 | Næstved BK |
Denmark legends whose careers overlapped Nielsen's
One rank above: Henrik Andersen at #26.
One rank below: Michael Krohn-Dehli at #28.
Denmark's editorial top five: Michael Laudrup · Peter Schmeichel · Allan Simonsen · Preben Elkjær · Brian Laudrup.