Borussia Dortmund's incoming sporting director Sebastian Kehl has promised a massive overhaul following Rangers 'deserved' victory.
Gio van Bronckhorst 's side secured a historic win against a European heavyweight, with the 2-2 draw at Ibrox rounding off an impressive 4-2 aggregate victory.
Despite the joy of reaching the last 16 for the Premiership champions, the post-mortem has ramped up for the Bundesliga giants.
Criticism continues to grow of boss Marco Rose during a lacklustre domestic - and now European - campaign.
In a post-match breakdown of the two legs, Kehl told Kicker : "We played well in the first half, the deficit was unnecessary.
"We turned the game around and had enough chances for a third goal. Rangers were rarely dangerous, we were dominant and didn't allow much.
"Something was possible.
"We conceded the 2-2 through another individual error and then no longer had the clarity and no longer the decisive situations.
"In the end we are deservedly eliminated after 90 minutes. That doesn't live up to our expectations."
"If we had played the second half with the same clarity, more would have been possible. That's why we have to say goodbye to the Europa League."
Concerns have now been raised by fans on the impact of the exit on Dortmund 's finances for next season.
With pressure ramping up on boss Rose, Kehl has promised a dramatic overhaul in the summer.
"Of course that's not enough for our demands and makes us think.
"We will work through it well and derive clear decisions from our analyses. We have to position ourselves completely differently in these competitions next season. There will be no 'keep it up'.
"The situation is a challenge, that's obvious, but we're taking it on resolutely."
