Hasan Salihamidzic blasted Bayern Munich as "inferior in all areas" in their loss to Bayer Leverkusen, as the champions slipped up in the Bundesliga title race.
A 2-1 defeat in the final game before the international break saw Julian Nagelsmann's side fail to reclaim top spot a day after losing it to Borussia Dortmund.
With the two sides set to meet in their first game back on April 1, Bayern will enter the crunch clash knowing a second reverse in a row could spell the end of their title defence.
Sporting director Salihamidzic was left fuming by what he perceived as a poor mentality throughout, and felt the visitors deserved nothing at BayArena.
"That's not what Bayern means," he told SPORT1 in discussing the performance. "We missed everything [that we] demanded from a team that won on Thursday. We were inferior in all areas."
"Confidence or not, we have to bring [our] mentality and greed onto the pitch. It is about the championship [race].
"We had two shots on goal in the last few minutes, but [we had] so little drive, [or] mentality, [or] assertiveness. I've rarely experienced that.
"This team is so good when the mentality is right from the start, but [they can be] just as bad when they don't do it and think that they can do everything with [their] quality."
Bayern had won three straight league games after losing to Borussia Monchengladbach last month but will now welcome Dortmund trailing their Klassiker rivals by a point.