Thomas Tuchel described Bayern Munich's 1-1 Bundesliga draw with Hoffenheim on Saturday as a "big step backwards".
Benjamin Pavard had given the hosts an early lead at the Allianz Arena, yet Andrej Kramaric sealed a point for Hoffenheim with a wonderful free-kick in the 71st minute.
Despite the setback, Bayern still retain a two-point advantage at the Bundesliga summit after Borussia Dortmund could only draw 3-3 with 10-man Stuttgart.
The result follows the heavy defeat to Manchester City in their Champions League quarter-final first leg in midweek, and Tuchel was left frustrated at his side's inability to get fans back onside ahead of the second leg on Wednesday.
"We didn't have enough speed, too few changes of pace, and we made mistakes," he said.
"We didn't get any security in. We started to defend carelessly. The display today was not enough; it was a disappointment for me. We have a lot of room for improvement today.
"It's extremely amazing because I felt the energy in the training, but it wasn't there on the field.
"We have to process it first, but it's definitely a big step backwards. Today was the moment to inspire fire and confidence. We didn't succeed at all.
"It's going to be difficult on Wednesday anyway [in the second leg against City], it's not going to get any easier now.
"We missed an opportunity to put ourselves and the fans in the mood to believe in it at all."
Bayern midfielder Joshua Kimmich endured a frustrating game, losing possession a team-high 16 times, and was at a loss to explain why Bayern struggled so much.
"Today was an absolutely bad performance from us, we know that," he said.
"After a 3-0 defeat you would actually think that you want to show a reaction. Especially in the Bundesliga, where it's very tight and where we need every point.
"I can't explain why we put in such a performance on the pitch today. It's lack of concentration, recklessness, we're not really there. We played without energy and then you can't win either.
"We all know that we need a completely different performance against City. We know we can do it too, but we have to put it on the pitch."