The enlarged first stage of the revamped Champions League was supposed to be a stroll for giants of European soccer like Real Madrid, Paris Saint-Germain and Manchester City.

It’s proving anything but that. In fact, heading into the sixth of eight rounds in the new-look, 36-team league format, there’s a growing risk of an embarrassingly early exit for Madrid and City — the winners of the last two Champions League titles — as well as PSG, the French champion which is doing by far the worst out of the four Ligue 1 teams in the competition. Twenty-four clubs will advance to the knockout stage, with the top eight qualifying directly for the last 16 and the other 16 going into two-legged playoffs.