By ESPNSTAR.com staff
The defending Bundesliga and DFB-Pokal champions ended their pre-season preparations with a 3-3 draw against Werder Bremen in the annual pre-season LIGA Total! Cup before losing on penalties, a week before their DFB Super Cup clash against Bayern Munich on Sunday.
Klopp has urged his charges to buck up if they want another successful season.
"I wanted them to take on board the things we have done in training," he told Bild. "I have seen nothing of the sort with the defence. That's not right.
"This has taught me an important lesson. We had no security. We do not have much to do, but we are preparing."
The manager does have good news to look forward to as star player Mario Gotze is set to recover from an eye infection which has saw him sidelined in the pre-season preparations.
"Improvement is in sight", Gotze told de Ruhrnachrichten. "There will be no problem [making the opening game]."
Dortmund's Bundesliga campaign begin on 24 August against Werder Bremen at the Signal Iduna Park.