The Schwarzgelben defender has rejected claims from the likes of Jose Mourinho that his side are the team to beat in Europe this term, and insists the Bundesliga comes first
Jurgen Klopp's men have had an impressive start to their European campaign, finishing top of a group containing Ajax, Manchester City and Real Madrid with an unbeaten record.
However, the Germany international has played down talks tipping his team as frontrunners for the competition this term.
"The fact that Jose Mourinho and Alex Ferguson regard it as a possibility is a real compliment for our team and the club," the 24-year-old told Kicker.
"However, it has no significance to where we will be at the end. There are maybe three or four title contenders. The usual suspects.
"Maybe we are directly behind them. However, we are not among the big favourites."
He then reflected on the current struggle his side are enduring in the Bundesliga this term, and stressed that they must improve their domestic form.
"I admit: I would rather have ten points more in Bundesliga and be out of the Champions League. For me, it is vital not to drop any points in championship matches that we actually should win," he continued.
"I want to reach second place [with Dortmund]. When I look at the quality of our team, we would sell ourselves short with a bad position in the table."
Dortmund's final game before the winter break is a DFB-Pokal clash with Hannover on Wednesday.