Determined Raphael Guerreiro has warned Rangers that Borussia Dortmund are gunning for Europa League glory but admits his team can't defend.
But the Portuguese international left-back agrees with club captain Marco Reus that they have major problems at the back due to their ropey rearguard.
Rangers head to Germany next week for the first leg of the play-off round, with Dortmund facing heavy criticism in their homeland after a poor season.
Reus lashed out at his own colleagues after recent defeats by insisting they have learned nothing defensively this season.
They trail Bayern Munich by nine points in the Bundesliga and are already out of the Champions League and the German Cup.
And Guerreiro has admitted it's all or nothing for BVB in the Europa League.
He said: "We definitely want to win the Europa League, even if there are still many strong teams in it. "Ending the season with a trophy like last year is our biggest goal.
"Our exit from the Champions League was very disappointing and we are now in the Europa League and we're there to win it.
"We're really up for it and will take it seriously.
"I can't deny that we do have problems defending together. We used the international break to train intensively on precisely this aspect and then we conceded five goals at home to Bayer Leverkusen.
"We conceded too many goals and often give our opponents too much space. It starts with the strikers and ends with us at the back. I don't exclude myself from that.
"The most important thing is that we're still second in the table. If we finally get our defensive problems under control, then a lot more is possible for us."
And Guerreiro admits the criticism the club has received this season is fully justified.
He admitted: "We play great games like against Freiburg, then we lose heavily at Ajax and then against Leverkusen and that's sobering.
"When we play well, we are brilliant, but if the opposite is true then we are in trouble.
"I don't think we have an attitude problem. Mentally, we're up for it. We need to communicate more and play better together.
"Look Bayern Munich have a squad with more depth and are economically much stronger than everyone else. We just need to concentrate on ourselves."
