BVB Dortmund manager Thomas Tuchel admits that his team didn't show up as they were beaten 1-0 by PAOK at Westfalenstadion on Thursday.
Robert Mak bagged a 33rd-minute goal for the Greek side to resign BVB to their second Group C defeat, meaning they finish the group-stage in second place behind FC Krasnodar of Russia.
"It was not particularly easy for us because we knew that we had pretty much already lost our battle with Krasnodar and that we were playing again on Sunday," Tuchel said. "It was also difficult for me to decide on a line-up.
"The absolute exertion you need, respect for the task and that real sharpness and passion about your game – we didn't have all those things you need to win games. And so that's why our performance looked like it was missing a certain something tonight. That's how it was possible to beat us today with one shot on goal.
"Our group was a complicated group, even if the teams in it were not the biggest names in European football. Amid all the harshness and criticism, it is important not to be unfair and to demand too much.
"The expectations were for us to win. However, we failed to ensure we put in the effort needed to win. The defeat hurts us and is unnecessary, but I don't want to over-dramatise it either. We still have three very important games ahead of us this year."
Dortmund's focus will now shift back to the Bundesliga, where they are second in the standings and face play at home against Frankfurt on Sunday.
"After the step backwards that we made in tonight's match, we now need to take two steps forward and show a complete change in our attitude," Tuchel added.
"We need to learn from what happened here, go through the difficult process of getting back on track and perform here on Sunday in a way which makes the fans happy."