It doesn't seem that long ago that Liverpool boss Jurgen Klopp was looking at title rivals Manchester City with envy over their wealth of talent available to them off the subs' bench.
In fact, it was only 18 months' ago where Klopp pointed out that City had made five substitutions in a match while still leaving the now-departed Leroy Sane on the bench.
Around the same time, it was Liverpool legend Steve McManaman who pointed out: "A squad like Manchester City's has more depth to it than Liverpool's. That's where he (Klopp) has to look.
"The squad can be deeper and better. They need to find more quality coming off the bench."
Fast forward to another post-successful transfer window for the Reds, though, and it seems Klopp may have finally reached a state of squad-like nirvana.
HAVE YOUR SAY : What is Liverpool's best lineup? Let us know your XI in the comments below.
With his side still battling for silverware on four fronts, Klopp was able to make a handful of changes for the FA Cup fourth round clash against Cardiff City on Sunday.
In came Caiomhin Kelleher, Kostas Tsimikas, Ibrahima Konate, Naby Keita and Takumi Minamino as amendments to the side which beat Crystal Palace prior to the winter break.
Those five players alone cost Liverpool a combined figure of more than £100million, while on the bench were a host of big-name stars: Thiago, James Milner, Joel Matip, Andy Robertson, Harvey Elliott, as well as new £50m signing Luis Diaz.
It is the arrival of the latter which seems to have propelled Klopp's squad into a new realm, with the Liverpool boss now finally possessing the alternative options to his front three that he has so long been lacking.
Diogo Jota's stunning form since joining the club was the first step on that ladder, while Diaz's acquisition now raises the prospect that the days of Liverpool's deadly front three being first choice could be numbered.
Jota has arguably already displaced Firmino in the Reds' attack.
Liverpool have dealt remarkably well without the services of Salah and Mane whilst the pair have been away on AFCON duty - something which would previously have struck fear into Liverpool fans and those inside Anfield.
Indeed, Klopp was not even certain if he would rush them straight back into action when welcome Leicester on Thursday, while the addition of Diaz appears to have taken Liverpool to that place their manager has long been trying to get them to.
Speaking in his programme notes ahead of Cardiff, Klopp said: "These boys over the last few years did an absolutely incredible job without, how you say, competition on different positions.
"They forced, they stretched really their limits – absolutely unbelievably, the development they had.
"We didn't bring in different players to create a competition. We bring in players to have solutions in different situations and that means now that the boys have to deal with it, that's the job they have to do.
"It means you are in the first line-up, so run your socks off and play as good as you can, as long as you can. And if you can't do that anymore, then another player has to be there who can replace you and do the same job – if possible, even better because he's fresher."
He added: "The more options we have, the more top-class options we have, the better it is for the club. That's hopefully the situation."
Certainly that now looks to be the case, with Liverpool arguably boasting two lineups which could compete at the top end of the table.
Kelleher has emerged as a worthy understudy to Alisson, while Tsimikas' development now gives Robertson more chance of a rest.
After last season's defensive issues, Konate's signing has given Klopp four solid options at central defence, while youngsters such as Elliott and Jones look to be the future of the Reds' midfield.
With the contracts of Salah, Mane and Roberto Firmino all ticking down as they head into their 30s, Jota and Diaz look to be the long-term successors in the frontline.
If you would consider any of Liverpool's positions as vulnerable to an injury it would probably be at right-back if Trent Alexander-Arnold were sidelined.
But with Milner and Joe Gomez both able to play in the role, and with youngster Neco Williams out on loan, Klopp still has decent alternatives.
Summer could see more changes in midfield, with Alex Oxlade-Chamberlain's future up in the air, while the jury is still out on Naby Keita, though Liverpool's reported interest in a new signing in that area would likely cover for any departures.
An alternative to Fabinho is the one position where you could argue they lack depth - as the midfield in lineup two would suggest - though either Henderson or Thiago could play there if required, as could Milner.
In attack, it seems Fabio Carvalho will join from Fulham too, another player who will fill the void of any exits with Divock Origi unlikely to get much of a look-in from here and expected to depart in the summer. Takumi Minamino could also be among those who may move on.
Furthermore, the likes of Kaide Gordon and Tyler Morton are part of a promising crop of youngsters looking to break into regular first-team plans going forward.
It hasn't been this way under Klopp before, hence the lack of a domestic trophy as he prioritised other competitions due to a perceived lack of depth to adequately rotate his hard-working squad.
But ex-Manchester United captain and pundit Roy Keane feels Klopp has finally got the perfect balance.
"Jurgen Klopp has got an ideal situation; he’s got these lads constantly under pressure because when you play for a big club you have new lads coming in who will want to challenge you for your place at that’s the aim of the game- challenges from within," Keane said on ITV.
"They get decent money for the lads they move on as well which is a huge part of the business but the strength in depth Liverpool have got now, it’s fantastic.
"The squad is a lot stronger than what it was a few years ago where he obviously made changes for cup matches."
Liverpool made hard work of their Championship opponents Cardiff in the first half at Anfield, but Jota's goal shortly after the break put them in control.
Klopp reacted by bringing on his new £50m signing Diaz and incredible talent Elliott - who is still only 18 - while giving Keita and Jones a rest, before his side eventually ran out comfortable 3-1 winners.
With a favourable draw at home to Norwich to come in the next round, and one cup final already booked, Klopp finally has Liverpool where he wants them.
Now he just has to decide who to pick.
