Jurgen Klopp unhappy with Anfield atmosphere ahead of Arsenal's visit
Liverpool had missed the chance to go top of the league on Sunday after a 0-0 draw with Manchester United but they blew away West Ham to book a record 19th appearance in the Cup semis on Wednesday.
Despite Liverpool's dominance, Klopp thought the atmosphere was lacking at Anfield.
"It's long ago that I said this — but I thought the first half a little bit, when the boys played really exceptional, I was not overly happy ... with the atmosphere behind me," Klopp told reporters.
"We changed a lot of things. We dominated West Ham like crazy. We missed chances. And I mean, if I would be in the stand I would be on my toes, 1,000%."
Liverpool partly opened their newly revamped Anfield Road Stand for the first time on Sunday, bumping up the attendance to 57,000 — the largest for 50 years at their stadium.
With leaders Arsenal set to visit on Saturday, Klopp said getting the right atmosphere was crucial.
"We need Anfield on their toes from the first second without me having an argument with the opposition coach. We need you from the first second," he added.
"If you really want, if it's too much football in December, I don't know. Sorry we have to play it as well. But if you are not in the right shape, give your ticket to somebody else."