The tie is locked at 1-all meaning Dortmund have to score and their manager says they won't let the hosts settle.
Kick off is at five past eight.
Meanwhile, the details of West Ham's contract to use London's Olympic Stadium as their new home have finally been revealed.
The Premier League club will pay 2-point-5-million-pounds a year in rent – but there are lots of other conditions.
They include the rent halving if they're relegated.
West Ham will also have to pay the London Legacy Development Corporation bonuses if they win certain events – including 1-million-pounds if they one day lift the Champions League trophy.
