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.
A talented goal-scorer, De Gier began his career at Cambuur Leeuwarden in 1991 and went on to play for several clubs, including Go Ahead Eagles, Willem II Tilburg, Lierse SK, NEC Nijmegen, Dunfermline Athletic and FC Twente.