The Bundesliga club travel to the Etihad following their 3-0 win over Copenhagen last week.
They'll come up against a familiar foe in Haaland, who has enjoyed a blistering start to his Man City career since his move from Dortmund.
He's already scored 12 goals in all competitions this season - including a brace against Sevilla in his side's 4-0 win.
And ahead of Dortmund's meeting with Man City, Reus was asked how to stop the Norwegian phenom.
"It’s simply sensational how he is performing at the moment in Manchester," he said of 22-year-old.
"It helps that his teammates are not the worst!"
Asked how to stop Haaland, the German replied: "How do you stop him? Good question. It’s not easy to stop him. One of the keys is not to be too late with your decisions, to be good at anticipating what is going to happen.
"You have to stay close to him to be able to stop him as much as possible for 90 minutes. Then you just have to hope he doesn’t have his best day."
Jude Bellingham was also quizzed about the star forward and he's not sure how to stop the goal-machine either.
"I’m not really sure to be honest!" He said in his pre-match press conference.
"He’s a player with a lot of quality and a lot of physical attributes that make him dangerous and like I said it’s not an individual task, it’s something that the team have to deal with collectively.
"If we stick together and try to do the right things without the ball then it can be possible."
Will Haaland net against his old team?
Topics: Erling Haaland, Marco Reus, Football, Manchester City, Borussia Dortmund
