Dortmund boss Peter Stöger admitted being disappointed with his side's performance after they were beaten 2-1 Red Bull Salzburg at the Westfalenstadion in the Europa League's round of 16 on Thursday.
The Austrian champions stunned their opponents early in the second half when Valon Berisha struck twice in the space of seven minutes. Andre Schurrle tapped in Christian Pulisic's cross in the 62nd minute to reduce the deficit, but the visitors held on as the Bundesliga side slumped to their first defeat in 2018.
Speaking after the game, boss Stoger, who took over at Dortmund in December following the sacking of Peter Bosz, conceded his side deserved to lose and will need to improve for the reverse fixture.
"I didn't like a lot about this match," he told the media in his post-match press conference as quoted by Goal.
"The first ten-to-15 minutes I thought that we were pretty acceptable in the game, but this feeling got less and less. The team didn't keep the speed high. So the game for the opponent became easier.
"Salzburg adjusted more and more during the match. They became braver and gained more confidence. In several moments we had the feeling we could change something about the result. But, between these good stages, our performance wasn't very dedicated. I'm not happy with it."
"We lost deservedly. That just was not okay. There was a lot missing, especially in the first half. That meant our opponents became more courageous, because we allowed them to be."
"That we allowed this to happen at home is a no-go."