Manchester City away. The big one. Go and make an impact, son.

Firmino was the man to be replaced. The Reds’ No.9 is usually made for games like this; games which require tactical acuity, a sure touch and positional discipline as well as relentless work rate, but his race was run inside 59 minutes this time. As Liverpool sought control, the Brazilian was sacrificed.

Klopp had insisted on Friday that Firmino remains “the difference maker” for the Premier League champions, and that critics who suggest his influence is waning, or that his modest goal return is becoming an issue, were to be ignored. “I can’t help those people,” he told his pre-match press conference.

His actions backed up his words. Firmino, left out of the starting line-up against Atalanta earlier in the week, was back in against City, with Klopp also retaining the trio that had done the damage in Bergamo – Mo Salah, Sadio Mane and hat-trick hero Diogo Jota.

It was certainly a bold approach – even Pep Guardiola seemed a little surprised when asked about it prior to kick-off – but it threatened to pay off as Liverpool bossed the early exchanges. Sharp and direct, the Reds’ fearsome foursome had Guardiola’s side on the back foot from the first whistle.

They led inside 13 minutes, Salah converting from the penalty spot after Kyle Walker’s ill-judged challenge on Mane. That’s eight goals in eight league games this season for the Egyptian; a start that only Fernando Torres (2009-10) and Robbie Fowler (1995-96) can match for Liverpool in the Premier League era.

Firmino is finding the goals a little harder to come by, of course. His last 31 appearances in all competitions have yielded only three goals, with only one in 12 outings so far this season.

It’s showing, too. He was hesitant when given a sight of goal inside a minute against City, opting to try and round Ederson and making a mess of it. In the second half, he wasted another presentable opening, firing well over the bar when there were options available.

In front of goal, his confidence seems lacking, and there were a few too many careless touches in general. The space was there, he just didn’t use it well enough, often enough.

Klopp is right to talk about everything else Firmino brings – his intuitive pressing, his ability to connect play, to attract defenders and open up space for others – but there is a reason why questions are being asked.

Perhaps this dip – and it is a dip – is to be expected. Liverpool are perhaps the most intense team in the world, and Firmino is the player who plays the most games for them.

His workload has been immense. Since the start of the 2017-18 campaign, he has made 166 appearances. Only Salah, with 165, comes close to that number.

Throw in a World Cup and a Copa America, in which he started every game of Brazil’s triumphant campaign, and it certainly adds up. Few top-level footballers, if any, give as much as he does, week in and week out. And he turned 29 last month.

Klopp knows that. Firmino, in form or not, remains central to his plans. Doubt doesn’t even come into it.

“I don’t have to say one word about Bobby, and how important he is to us,” he said last week. “I don’t waste my time with that.”

Perhaps not, but with Jota – seven goals in 11 appearances since joining from Wolves – settling in nicely, and with Shaqiri back fit and looking bright and hungry, at least Klopp has the option to rotate his attackers, where perhaps that hasn’t been the case in recent seasons.

For Firmino, that could well be good news. After all, if anyone deserves the odd rest from time to time, it’s him. And if anyone has enough credit in the bank to pay them through a slump in form, it’s him.

Klopp, though, will hope his spark returns soon enough. And when it does, Liverpool will take some stopping.

Again.