The BVB trainer was quick to make clear that his team should forget their exploits in Europe's elite tournament and concentrate on their match with the Oh-Fives
BVB qualified to the round of 16 of Europe's elite tournament as Group D winners, leaving the likes of Real Madrid and Manchester City in their wake.
Their domestic form, however, has not been that impressive as they currently sit only fourth in the standings, and Klopp has demanded a professional performance on Saturday against Mainz.
"The task is clear and it will not be easy. But, its like that for all teams that play in European competitions," Klopp said at a press conference.
"Its not a walk in the park to have three games a week. I expected that and its a nice problem to have. We have dropped some points in the league and we should not do that again.
"You don't get the points easy in Mainz. We need to work hard and do everything we can to be prepared."
Klopp also had a word on Borussia Dortmund's exploits in the Champions League this season, making clear that BVB's success is hard-earned.
"Nothing about it was easy. Not a single second of it," he continued.
"On Wednesday I had the feeling that even if Ajax scored another goal it would still be okay. But, all the other games were hard until the last second.
"Let me remind you of the game against Ajax at home where we scored three minutes before the whistle. It was an amazing game, and those against City and Real Madrid were too.
"None of them were easy. We know what it took. The group was as difficult as it sounded."