Berlin (AFP) - Borussia Dortmund coach Peter Bosz admitted their third straight defeat in the Bundesliga "hurts" as the club's dire form continued ahead of Tuesday's Champions League clash against Tottenham Hotspur.
Dortmund are winless in their last five league games, collecting just one point from a possible 15, after losing 2-1 at VfB Stuttgart on Friday.
They last won a Bundesliga match in September and could finish the weekend nine points behind leaders Bayern Munich.
The defeat in Stuttgart further dented fragile confidence before facing Spurs in Europe and next Saturday's derby showdown against fierce rivals Schalke.
To make matters worse, star striker Pierre-Emerick Aubameyang was suspended in Stuttgart for "disciplinary reasons".
Bosz lamented both the performance and "ridiculous" opening goal, which Dortmund conceded after just five minutes.
"That hurts a lot. We came here to win and so we are very disappointed," fumed Bosz.
"How we conceded the goals was almost ridiculous.
"We played well in the first half, but if you concede goals, then it becomes difficult.
"The players did a really good job after going behind and we tried to play football.
"We have to continue, we will not give up," he added with an air of desperation.
- Defensive mix-up -
Without Aubameyang and injured US international midfielder Christian Pulisic, Dortmund were on the back foot after only five minutes.
A defensive mix-up between Marc Bartra and goalkeeper Roman Burki allowed Stuttgart midfielder Chadrac Akolo to score the hosts' opener.
Maximilian Philipp levelled on the rebound from Andre Schurrle's missed penalty just before the break for Borussia.
However, Josip Brekalo's low shot through Burki's legs in the second half sealed Stuttgart's win.
After picking up just two points from their first four European matches, Dortmund could be knocked out of the Champions League in the group stage even if they beat Tottenham, should Real Madrid defeat APOEL Nicosia on Tuesday.
Bosz took over at the start of the season, but after Dortmund won six of their opening seven league games, their form has nose-dived.
The Dutchman is cutting an increasingly frustrated figure, but he retains the backing of Dortmund's CEO Hans-Joachim Watzke, for now.
"The way things are working behind the scenes is outstanding," said Watzke.
"He is totally honest, totally calm and relaxed, very analytical.
"You can discuss everything with him.
"He is also decisive but takes all decisions and their consequences without complaining," added Watzke in a thinly-veiled dig at Bosz's predecessor Thomas Tuchel.
- 'No special rights' -
However, Bosz's situation will only become more precarious unless results improve, and Aubameyang's latest indiscretion does nothing to help.
Dortmund disciplined the Gabonese striker last year for flying to a party in Milan without permission.
He also fell offside with club bosses for shaving the Nike logo into his hair, even though Dortmund are sponsored by Puma.
German magazine Kicker claim Aubameyang was suspended for repeatedly coming late to training and for an unauthorised video shoot at Dortmund's training ground on Wednesday.
"The suspension was disciplinary. A group needs some rules and from time to time you have to sharpen your senses," said Watzke.
"Aubameyang is actually an awesome lad, but he has no special rights.
"Things must be sanctioned, just like in a family or in a school class - you have to say 'stop there'.
"He is, and remains, our player."