He began his career playing amateur football in his home town for BVH Dorsten, a team which two of his brothers, Heinz and Erich, also played for,[5] and helped the club achieve promotion to the Verbandsliga, the highest level of amateur football at the time.
[4] Despite being the club's second highest scorer in the 1968–69 season, Pröpper was not a regular in the side, and was sold to Wuppertaler SV for DM 30,000 in 1969.
Pröpper scored 21 goals in his first Bundesliga season, helping the club finish in fourth place and qualify for the UEFA Cup.
Despite reported interest from other Bundesliga clubs,[2] Pröpper remained at Wuppertal for the rest of his playing career until his retirement in 1979.
He scored 170 goals during his ten years at Wuppertal, taking his career total to 258, making him the eighth highest top scorer of all-time in German football.