Graham Potter issues rallying cry to fans as Chelsea host in-form Dortmund
The Germans have won their last 10 games in all competitions, including eight in the Bundesliga where they are second on goal difference behind Bayern Munich.
Chelsea have been knocked out of both domestic cups and sit 10th in the Premier League, which leaves the Champions League as the club's only realistic shot at a trophy this season.
But the fans were left frustrated after Chelsea failed to win for six games in a row after spending nearly 300 million pounds in the January transfer window - more than Bundesliga, LaLiga, Serie A and Ligue 1 clubs combined.
"Fans are always entitled to air their views and they've been suffering like the rest of us in terms of the results we've had. The reception and support we had was fantastic," Potter told reporters on Monday ahead of the second leg.
"They know the importance of the game tomorrow night. They want the team to go through, to progress, and they know how important they are.
"We want to make sure it's tough for Dortmund away from home in the Champions League and we need our supporters for that."
Potter said Chelsea's long-awaited victory, which came against Leeds United on Saturday to snap their winless run, had put a smile on the players' faces ahead of the Dortmund game.
"Like everyone connected with Chelsea, it's better when you win. Everyone is a little happier," he added after the 1-0 victory.
"We've had some games where we could have scored more than one and we need that performance tomorrow night. We're playing against a top team, a team that is in a good place with the wins they've had."
Chelsea will take a late call on defender Reece James (23) after he missed the Leeds match with a thigh injury while Christian Pulisic (24) is back in the squad, but the game is too soon for midfielder N'Golo Kante (31) who has been sidelined since August.
"It's a complex one with him (Kante) because he has had a long time out. It'll be a case of how we get him back up to speed to play Premier League or Champions League football," Potter said.
"He won't be able to go back in for 90 minutes any time soon, but the fact he is with us is exciting."