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The Liverpool manager could not remember a worse performance than his side's 3-0 thumping.
Solly March scored twice early in the second half before Danny Welbeck added a fine third as the Seagulls beat the Reds at home for the first time since 1961.
Liverpool, which slid to ninth, was second-best throughout and has started a calendar year with two league defeats in a row for the first time since 1993.
It has also lost as many as five away league matches in a single season for the first time since the 2017-18 campaign.
But this might have been the worst of the lot, with Liverpool leaky at the back and profligate in attack, giving up 16 shots and failing to net with any of its six.
Brighton, which moved up to seventh, controlled the ball with a huge 61.9 per cent of the possession.
"Bad, really bad," Klopp told BBC Sport afterwards.
"I can't remember a worse game. It's not difficult maybe.
"Brighton were the better team, it was well deserved. They played really well.
"It was a very organised team against a not very organised team. We gave the ball away, the spaces were too big and we couldn't push up.
"That is obviously not good, especially against a super well drilled side like Brighton.
"They got more confident and we did the opposite.
"I can imagine they are very happy because it was a great performance and we made it too easy in too many moments.
"I had an idea to change the formation, which was to try to help the team.
"That was the idea but we never did it properly. We were always a bit in between and that's the worst thing you can do.
"We could have done better but we didn't and that's why I looked the way it did.
"We need to be creative with the options we have. What I saw today from my team was that they were not really convinced by it. That's it."
Asked if he was concerned by his side's display, Klopp said: "Yes, how can you not be after a game like this? I cannot stand here and say it didn't happen.
"Of course, we have to be very concerned about it."
In a separate interview, he added: "Doing better should be easy, because this is a really low point. I can't remember a worse game.
"To improve that will be not too difficult. From this game we can pick up absolutely nothing apart from things that do not work."
