In the 1949\/50 season the Soviets would not allow Hertha to play against East German teams , because they had signed some players and a coach who had left the Dresden club SG Friedrichstadt for West Berlin . Hertha was banned from play against East German teams in the 1949 â `` 50 season after taking on several players and a coach who had fled the Dresden club SG Friedrichstadt for West Berlin .