 A defender in his professional career, Bernard Dietz played in 495 Bundesliga matches for MSV Duisburg and FC Schalke 04, scoring 70 goals in his Duisburg years and seven in his days with FC Schalke 04 in the top tier of German football.Leaving Duisburg for Schalke in 1982 caused him to feature 34 times (one goal) for the Gelsenkirchen outfit in the 2.Bundesliga of 1983–84 after the club had been relegated from Bundesliga in Dietz' first season with them.