Coach Markus Babbel has admitted he is mystified after nine-man Hoffenheim was hammered 4-0 at home by Eintracht Frankfurt to leave it bottom of the Bundesliga.
It was Hoffenheim's third defeat in three competitive matches since suffering a shock 4-0 defeat at fourth division minnow Berliner AK 07 in the German Cup a fortnight ago, then a 2-1 loss at Borussia Monchengladbach last weekend.
Things went seriously awry for Hoffenheim at its Rhein Neckar Arena as both midfielder Sejad Salihovic and defender Stephan Schroeck were sent off in the second half for receiving second yellow cards.
"I have no logical explanation," ex-Liverpool defender Babbel, who has coached Stuttgart and Hertha Berlin, said.
"This performance is a mystery to me. This is definitely a bad start.
"This is bitter for the guys, it has hurt us."
Hoffenheim's miserable afternoon took a turn for the worst when midfielder Alexander Meier scored Frankfurt's opening goal on 39 minutes before captain Pirmin Schwegler added a second just before the interval.
Hoffenheim had midfielder Sejad Salihovic sent off on 70 minutes for two quick bookings, and Philippines defender Stephan Schroeck followed after he was shown his second yellow card three minutes later.
The host's misery was compounded when Meier netted his second with a penalty on 83 minutes before Martin Lanig headed the fourth in the 90th minute.
"After going 1-0 down, you could see the boys were shocked," said the 39-year-old Babbel.
"I was very disturbed, because we didn't then respond positively, so we were 2-0 down at half-time.
"During the break, I knew that it is difficult to change things around.
"I tried to give us a fresh start with a few replacements, but the two sendings off threw that out of the window."
With a two-week break coming up after the international matches, Babbel admits he has plenty of work to do to stop the rot ahead of Hoffenheim's next match against Freiburg on 16 September.
Babbel has reshuffled Hoffenheim with ex-Liverpool striker Ryan Babbel being sold to Ajax, fellow Dutchman Edson Braafheid loaned to FC Twente, while ex-captain Andreas Beck was left out of the matchday squad.
Hoffenheim claimed a vital 3-1 win against second-tier Kaiserslautern in the first leg of the Bundesliga play-off.