For the fourth time in a row on a weekend preceding a UEFA Champions League encounter, the Westphalians succumbed to defeat in the Bundesliga, with three of those on home soil.
All of which leads to the logical suggestion that Dortmund are struggling to split their focus between the two competitions. When Jürgen Klopp's charges take to the field in the Bundesliga knowing they are in European action only a few days later, something seems to go awry. Furthermore, they have also struggled to juggle their DFB Cup assignments, going down 1-0 at home to Bayer 04 Leverkusen after booking a quarter-final berth.
It is a curious pattern. When BVB are on top of their game they are a match for anybody, yet all too often the cogs have simply not been turning in the same direction. Their tally of four league defeats at home is already double the amount of games they lost at the Signal Iduna Park in the 2010/11 and 2011/12 title-winning seasons combined.
Not a nice feeling
Imperious victories have been intermingled in those disappointments, though, and for the first five games of the season, it seemed like Klopp's boys were in the hunt to win back the Bundesliga from Bayern. Consistency is the buzzword and the lack thereof has proven to be Dortmund's achilles heel. It also goes some way to explaining the 23-point deficit on Bayern after just 25 games.
"It isn't a nice feeling," said striker Robert Lewandowski at the weekend. "We need to talk to each other to establish why we performed the way we did against Gladbach. It's something I hope doesn't happen again." Lewandowski is not alone in that respect. If Dortmund are to take something out of this season - they remain in the hunt for two trophies - Klopp needs to put his finger on what is disrupting the system.
Last term, Klopp singled out his defence for their failure to match Bayern stride for stride, yet when it came down to the knockout environment of Champions League games, that weakness was less evident. Indeed, while Dortmund still conceded regularly in Europe last season, they more than made up for it with their frontline, the continent's third most prolific attack behind Bayern and Real Madrid CF - the side they eliminated masterfully in the semi-finals.
Dortmund conceded 42 in the league last term and are already up to 29 this year, suggesting that work still needs to be done at the back. Injuries have certainly played their part, with Klopp deprived of his entire back four at one stage this season, a situation that has bred instability. Yet as soon as the Champions League anthem sounds, Dortmund switch into beast mode; an animal prowling the continent in search of their next prey.
That has likely been at the heart of their domestic woes this season. Losing the Champions League final to Bayern last year hurt and the players' eagerness to go one better this time around has affected their domestic form. Provided BVB get the better of FC Zenit on Wednesday and keep progressing though, nobody at the club will mind too much.
Check out Dortmund's defensive frailties against Gladbach last weekend on the Bundesliga's official YouTube channel;