Liverpool's progress under Jurgen Klopp has been marked by key signings at each stage. After the defending Premier League champions slipped 10 points behind Manchester City with a 4-1 defeat to Pep Guardiola's table-toppers, Jamie Carragher explained why and where they must strengthen now.
Sunday's defeat at Anfield - Liverpool's third home loss in the league in a row - led to Klopp saying afterwards finishing in the top four was now his side's "main target" this season, with their Premier League crown appearing to slip out of their grasp.
However, while Carragher believes his former club will come back strongly next season, he says Liverpool will also need some key additions in the summer transfer window to boost a first XI which has remained largely unchanged since the 2018 Champions League final defeat to Real Madrid in Kiev.
"Initially, when Jurgen Klopp came in, Liverpool were a team who were sixth or seventh," Carragher said on Monday Night Football.
"His first summer he brought in three players - Joel Matip, Georginio Wijnaldum, and Sadio Mane. That then took them into the Champions League.
"Over the next 12 months he then brought in Mohamed Salah in the summer, Virgil van Dijk in the January and Alisson on the back of the 2018 Champions League final. That then took them on again, to the Champions League win and the title.
"I think Liverpool are back at that stage where they need those three players to come in again to give them that jolt."
Carragher highlighted the high proportion of Premier League minutes Klopp's preferred XI have played since that Champions League final in 2018 and believes the drop-off we have seen from Liverpool this season could be attributed to mental and physical fatigue for a group of players who have played so often over that period.
"We're talking about intensity and Liverpool maybe dropping off and looking a little bit jaded physically - and how similar this [2018 Champions League final] team is to what Liverpool have today," Carragher said.
"That back four, it's still the same two full-backs, Van Dijk when he's fit plays. Dejan Lovren has moved on but Matip would have played that final if he was fit, and Joe Gomez was at the club.
- Get Sky Sports | Get a Sky Sports Pass
- What's behind Liverpool's slump?
- Gary Neville: Liverpool look drained
"The midfield two is still Wijnaldum and Jordan Henderson, first choice, and James Milner has played the last four or five games as well. That's the one area where Liverpool did bring someone in, it was Fabinho. So we are talking about one player [coming in].
"And then you've got the front three.
"It's still the same team that's been together for three years.
"When you look at the percentage of Premier League minutes played from August 2018, this is a team that have gone to the well for three years and produced unbelievable moments, trophies for this club. And that's why I find it a little bit hard to be too critical of what I'm seeing at the minute.
"This is not an attitude thing. This is not a team who think, 'We've won the league, we've made it'. They just haven't stopped for three years. That's why I say they need a little bit of help."
The three positions where Liverpool need a boost
Carragher argued Klopp could not have managed his players' workload much better than he has, simply because he does not have the depth in reverse to rest and rotate his starting XI.
Instead, the Sky Sports pundit picked out the three key positions Liverpool must now strengthen to kick on again.
"People say, 'Well, Jurgen doesn't rotate'. Liverpool haven't got the quality of squad and back up of other clubs. Liverpool wouldn't have won the trophies they have done over the last two or three years if he'd rotated.
"I still think they will be back - but they need three players.
"They need a centre-back - maybe he's joined now in Ozan Kabak - they need someone to replace Wijnaldum, and they need someone in the front three.
"And I'm not talking about players on the bench. I'm talking about players to come into the team like Matip, Wijnaldum, and Mane did, like Salah, Van Dijk, and Alisson. That's what Liverpool need."