Borussia Dortmund returned from Rome with a black eye following Tuesday's 3-1 loss to Lazio in the Champions League, a stern warning that they must shape up quickly or face an early exit from Europe's elite club competition.
The Germans, finalists in 2013, hardly put up a fight and their only glimmer of hope of getting something from the match was when Erling Haaland cut the deficit to 2-1 in the 71st minute.
But the Italians put the game to bed five minutes later to hand Dortmund their second loss of the season following a Bundesliga defeat in the second round of matches.
"If we play like that then we can forget about advancing to the next round and the coming weeks will be very intense and hard," said Sebastian Kehl, head of the Dortmund players' department.
"Obviously this is not the way to present oneself. We absolutely deserved to lose. Only a few players came anywhere near their limits."
Dortmund are bottom of Group F, with Club Brugge on top with Lazio after beating Zenit St Petersburg 2-1.
With the Ruhr Valley derby against Schalke 04 on Saturday, Kehl knows there is no time to waste.
"Our performance was inexplicable. It was just desolate," he said. "We have the derby on the weekend and there we have to expect a different fight. We have to present ourselves differently."
Dortmund host Zenit next Wednesday in their second Champions League group game and coach Lucien Favre has his work cut out.
"This is not a good start for us. I said we can lose a game because there is a home match and four more matches," said Favre.
"But this was not good. This is a fight and we have to be present. I am very disappointed."
(Reporting by Karolos Grohmann; Editing by Peter Rutherford)
