When he was 16, Posipal's family relocated to Germany. In his youth his sportive activities focused on swimming and track-and-field as well as handball. In 1949 he joined Hamburger SV as then coach Georg Knöpfle was looking for a forward.
When he was sixteen years old, Posipal's family relocated to Germany.  In his younger years, he enjoyed participating in swimming, track and field, and handball. In 1949, he joined Hamburger SV, a team coached by Georg Knöpfle.