He scored the final goal in Ajax's former stadium "De Meer" on 28 April 1996 for Willem II.

Born in Schijndel, De Gier started his career at BVV Den Bosch, making his debut in August 1988 at the age of 20.

[1] A prolific striker, De Gier joined Cambuur Leeuwarden in 1991 and later played for Go Ahead Eagles, Willem II Tilburg, Lierse SK, NEC Nijmegen, Dunfermline Athletic and FC Twente.

[citation needed] De Gier began his managerial career in professional football on 1 January 2016 as a head coach of Eerste Divisie club Almere City, replacing the dismissed Maarten Stekelenburg.

In February 2017, the club extended its expiring contract until the summer of 2018 with an option for another year[4] On 25 May 2018, NEC Nijmegen announced that they had appointed De Gier as head coach as of 1 July 2018.