The game changed on Sadio Mane’s 37th-minute red card after the Senegal striker caught City goalkeeper in the face with a reckless high foot as he chased Joel Matip’s long through ball.
“If City take too much confidence from this game it would be a mistake and if we lost too much confidence it would also be a mistake,” said Klopp.
While it was true that Liverpool weren’t heading for the heaviest defeat of his reign before Mane’s dismissal, the way his side capitulated after the incident should be a concern to the Reds boss.
They were already trailing to Sergio Aguero’s 24th-minute goal — his sixth in six games against Liverpool at the Etihad — before Mane was shown a straight red for catching Ederson, who was treated for eight minutes but thankfully hasn’t suffered any serious injury.
From there, City ruthlessly took apart the remaining 10 men in a masterful display, controlling the ball and territory and creating chances via the brilliant vision of Kevin de Bruyne, dangerous crossing of Benjamin Mendy, and individual brilliance of substitute Leroy Sane.
Gabriel Jesus scored twice either side of half-time, Sane added two more late on, but it could have been worse for the hapless visitors, who folded badly and surprisingly showed little spirit.
Pep Guardiola heeded Klopp’s words not to get too excited by the result but was delighted by the performances of his Argentinian striker, particularly the way Aguero selflessly gave the ball to Jesus for the third to kill off any comeback hopes rather than try to score himself.
“That means a lot for me, what Sergio did — a lot, a lot,” insisted Guardiola, who has not always praised Aguero in the past when others have been impressed.
“They are both good guys and exceptional players, their relationship is top. You have all known Sergio for a long time. Of course, they both want to score goals and we need that, strikers are always: ‘I want to score more than my team-mate’, but it is still important to have the ability to choose the right decision, as Sergio did when he was one against the goalkeeper.
“When it happens the next time, Gabriel is going to do that for Sergio.”
Liverpool had caused problems before the opening goal with Mohammed Salah posing a threat on the right wing but his end product was often too wasteful. He had the Reds’ best opportunity, which was well saved by Ederson, and it saw him hauled off at half-time for new signing Alex Oxlade-Chamberlain.
Mane was Liverpool’s biggest threat and he will now miss their next three Premier League games with any appeal unlikely to be successful.
He will at least be back for the start of the Champions League on Wednesday when they face Sevilla. Philippe Coutinho is also likely to be back after his protracted Barcelona saga ended when the transfer window shut.
He was left out of the squad at the Etihad despite playing in Brazil’s World Cup qualifiers. Klopp felt he wouldn’t have made too much difference to the outcome. “I’m not sure it’s quite that easy, but if it is that easy — if we bring him in and then everything is great again — then that’s cool,” said the German.
“With Phil, we didn’t always create more chances against City in the past. Yes we scored more often in some games.
“This was the decision we took [to leave him out]. If people blame me for this, no problem, but it was a decision taken for the season.
“He came back after a long flight, after three weeks without playing, we have matches next Wednesday, next Saturday, we play, play, play, play. So we thought: ‘Let’s give him three or four days’ proper training — and then he’s available for us’, which is very good news.”
Ederson 8 (Bravo 45, 6), Walker 6, Danilo 7, Stones 7, Otamendi 5 (Mangala 71, 5), Mendy 7, Fernandinho 7, De Bruyne 9, D Silva 7, Aguero 8, Jesus 7 (Sane 57, 7). Subs not used: Gundogan, Delph, B Silva, Foden).
Mignolet 7, Alexander-Arnold 5, Matip 5, Klavan 5, Moreno 6, Wijnaldum 5 (Milner 58, 5), Henderson 5, Can 5, Salah 5 (Oxlade-Chamberlain 46, 4), Firmino 5 (Solanke 67, 5), Mane 4.
Karius, Lovren, Gomez, Sturridge.