Jurgen Klopp says Liverpool's defensive work needs fixing after his side beat Leicester 2-1 to win the Premier League Asia Trophy on Saturday.
Liverpool had to come from behind to win in Hong Kong as Islam Slimani headed home for the Foxes in the 12th minute.
Goals from Mo Salah and a stunning strike from Philippe Coutinho saw Liverpool secure the victory, and while Klopp was pleased with the result, he acknowledged that his side need to improve defensively.
"Two games, two wins so that's of course the best thing," Klopp told Sky Sports after the game. "You can see it was difficult again and it was not 100 per cent of our physical ability.
"Players like Riyad Mahrez and Jamie Vardy, they cause you problems so we're a little bit too late in the mind because the legs are tired.
"I thought we could have defended the first goal seven times already, but in the end it is a cross and a free header so it's not nice but it's what happens. We came back and even before the good goal, we were already the dominant side and playing good football so it was all OK.
"I liked everything I saw but that [defensive work] is something we need to fix 100 per cent. I know it is pre-season and we can change it but it is something I don't like already so we need to work on it."
Even when quizzed on Coutinho, who has been reportedly linked with a move to Barcelona, Klopp continued to hammer home his desire to improve Liverpool's back line.
"There is no doubt about these things [Coutinho's commitment to Liverpool], so why should he prove it then? He is a fantastic footballer and a fantastic boy," Klopp added.
"He had a few wonderful moments offensively but we have to stabilise ourselves in defensive situations. Like I've said, you can't train for being a real challenger and a real defender in these moments."
Klopp, who said he has been pleased with how his side performed during their pre-season tour, added: "It has been extraordinary and the most difficult circumstances for a camp, I have to be honest.
"It has been a fantastic tournament in a fantastic ground. We worked hard in training, that's clear, but for the players it has been unbelievable how they played in a game like this. Both teams were happy after 75 minutes, thank you very much and let's go home. It was too much.
"But I'm happy that we came here now, we had a few moments which really made us stronger as a team and I'm completely fine with it.
"The second phase is now starting in Germany. We need to be ready for the start [of the Premier League] because it is not possible to go through a pre-season like this and everything feels easy, then a hot August in England is coming.
"That's what we have to prepare for but everything can be improved although what we have done so far is completely OK."