Chelsea are in Champions League action this week for the first time since their controversial squad decisions.
They left first choice new centre back Benoit Badiashile out, in order to fit in Joao Felix up top. That means Kalidou Koulibaly is going to play alongside Thiago Silva.
Dortmund are a team known for having a pretty flimsy defence, so if we keep on the front foot and keep them under pressure we should be alright.
But if it comes down to some tense final moments or a crucial Koulibaly mistake… expect this story to come right back to the surface.
You can see their preview in the clip embedded here: