Dortmund coasted to a 2-0 victory in their last-16 tie at Stadion Ludwigspark, controlling the match from start to finish even though a number of first-team regulars - such as Robert Lewandowski and Jakub Blaszczykowski - were rested.
The Bundesliga outfit's dominance was illustrated by the fact they enjoyed 84 per cent possession throughout the game, and coach Klopp was delighted with his side's professionalism.
"An upset was never on the cards," he told Dortmund's official website.
"We played a great game even if it only finished 2-0. Our finishing could have been better, but everything else was perfect - it was fun to watch.
"The lads with little match experience played a fantastic game - Jonas Hofmann, Julian Schieber ... and Oli Kirch was the outstanding player. This was really good - it looked fluid despite little playing time."
Hofmann set up Schieber for the opening goal after just 19 minutes, before the latter returned the favour for the 21-year-old to seal Dortmund's progress four minutes into the second half.
And midfielder Hofmann was pleased with his personal performance, adding that he hopes his display will earn him more first-team opportunities.
"It's always nice to be involved in goals," said the Germany under-21 international.
"As a young player, I always try to make an impression, and today I managed to do that in making and scoring one."
