Former Rangers goalkeeper Stefan Klos has warned Borussia Dortmund it will be "difficult to survive" at Ibrox as he heaped praise on the Scottish champions.
The German won the Champions League with BVB before a successful spell between the posts in Scotland.
That means he had a keen eye on the first leg of the Europa League play-off at the Westfalenstadion as Gio van Bronckhorst 's side ran out 4-2 winners.