He coached the Denmark national football team that won the UEFA Euro 1992 tournament.

Nielsen was mostly known for his career as a football coach, but he played for Odense BK, and was capped twice for Denmark as a defender.

Nielsen was mentioned early in the race for the job, but the Danish Football Association decided to look abroad for a new coach.

The match finished 2–2 in regular time and with a 5–4 win in the penalty shoot-out, Denmark secured a place in the final against reigning world champions Germany.

On the 25 August 1993, Michael Laudrup made a comeback in a 4–0 victory home against Lithuania after having reconciled with Nielsen.

Laudrup never achieved the same success under Nielsen as he had enjoyed during the 1980s with Piontek as coach and Preben Elkjær next to him in the attack.

[3] Nielsen went on to coach the Finland national football team and came close at securing a play-off game for the 1998 World Cup in France.

[citation needed] Nielsen died on 13 February 2014,[4] following the unsuccessful removal of a brain tumour in September 2013.