BVB are currently languishing down in 15th place in the German top flight but their former forward says Jurgen Klopp's men are capable of beating anyone on their day
Robert Lewandowski has warned his Bayern Munich team-mates not to underestimate Borussia Dortmundahead of Saturday's Bundesliga showdown at the Allianz Arena - despite his old club's disastrous start to the new season.
BVB finished as runners-up last term but they have lost six of their opening nine games of the 2014-15 campaign, leaving them languishing in 15th place in the standings, just above the relegation zone.
However, Lewandowski, who left Dortmund for Bayern on a free transfer during the summer, is quick to point out that Jurgen Klopp's side have been hit hard by injuries and thus believes that they cannot be written off ahead of this weekend's game in Bavaria.
"This is an important game: Dortmund are always dangerous," the striker told Sport Bild. "They can beat anyone in a one-off game.
"They have so many players injured and they have the whole season to turn things around.
"It has all gone wrong at the start but Dortmund are always difficult to play against.
"They still have great players, so the biggest mistake for us would be to underestimate them."
Lewandowksi also insisted that he does not derive any satisfaction from the fact that Dortmund are struggling so badly without him, revealing that he still looks out for their results every weekend.
"As soon as our games are finished, the first thing I want to know is how Dortmund have fared," the 26-year-old attacker confessed.
"It is not as if I am pleased by Dortmund defeats."
However, Lewandowski admitted that he is loving life in Bavaria, despite the fact that he is struggling to be as prolific as he was in Dortmund.
The Poland international, who has hit five goals in 12 appearances in all competitions, insists that he is feeling more and more settled with each passing game, thanks in no small part to former BVB team-mate Mario Gotze.
"I'm feeling much better in Munich now," he explained. "I guess you can say that I have arrived.
"But things will get even better. Mario and I already got along very well at Dortmund. Our rapport was good and in Bavaria it is getting better.
"Here, there is tremendous pressure before every game. And even after three or four goals, there is no let up. We always want to be at full throttle.
"We are never satisfied - even though many of our players have already won everything. This formula for success here is outstanding."
Bayern are undefeated going into this weekend's game against Dortmund and hold a four-point lead over Borussia Monchengladbach at the top of the Bundesliga.