Reigning German Bundesliga champions Dortmund have had a shaky start to the season so far, recording two wins, a draw and two losses in their opening five league matches.
And with their opening Champions League game against Arsenal looming, Klopp admits his team have a lot of work ahead of them, although he admitted Hertha were worthy winners on the day.
"It was tough today [Saturday], we really had to invest a lot to get a grip on Hertha," Klopp said on Dortmund's official website.
"They [Hertha] played sensationally and have [the win] that they now deserve.
"We must certainly play much better, especially creatively.
"We have experienced many great moments in this stadium [Signal Iduna Park], but I hope today [Saturday] helps the development of the team."
Dortmund will plays hosts to Arsenal on Tuesday, before they resume Bundesliga action on Sunday away to Hannover.