Liverpool must be looking back on the transfer business it completed in 2023 with renewed fondness, as the players who arrived as part of that midfield rebuild form the backbone of a convincing title challenge. But it was a summer just as much defined by the players who did not arrive, not least Moises Caicedo.

The saga is familiar to most. Almost out of nowhere came the exciting news that Liverpool had tabled a $139m (£111m) bid for Caicedo, seemingly deeply out of kilter with the typical FSG model.

The same summer had seen Liverpool shy away from Jude Bellingham, after all, conscious of using up all its budget at once. And yet here was Jurgen Klopp confirming the big-money bid submitted to Brighton, with a deal surely at an advanced stage for the news to become so public.

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But Liverpool had moved too late. Caicedo had been sold the dream of a move to Chelsea, and all the Reds succeeded in doing was forcing Todd Boehly to fork out a little extra cash to get the deal over the line.

The final value of the transfer was £115m, which is $144m at the current exchange rate. Eye-watering, no doubt, but there was a sense that Chelsea had got the truly stand-out player on the market.

To make matters worse, it had got the back-up option too, signing Romeo Lavia for good measure. Liverpool, who appeared from the outside to be scrambling, moved for Stuttgart veteran Wataru Endo — reading between the lines, it seemed likely that the club had leaned on the expertise of Bundesliga old hand Jorg Schmadtke, himself a stop-gap option in the post of sporting director.

At the time, it still went down as a decent transfer window for Liverpool. There was cautious optimism about the deal for Ryan Gravenberch, while Alexis Mac Allister and Dominik Szoboszlai seemed like shrewd additions too.

But there was a lingering sense that Liverpool had failed to fill the Fabinho void. Even last season, that feeling was not completely shaken — the surprising prominence of Endo showed that Klopp still felt the need for a combative presence at the base of the midfield.

Having said that, Endo's regular involvement was also testament to just how much he was surpassing expectations. In truth, he was matching Caicedo stride-for-stride, at approximately one-seventh of the price.

Since the arrival of Arne Slot, it has been a more specialized role for Endo, coming on toward the end of games to help Liverpool see out results. But that has been important in and of itself, and Liverpool will be more than satisfied that it has comfortably got its money's worth from the signing — a feeling that will only be intensified if the season ends in silverware.

In fact, over the last year, FBref lists Endo as the single most similar player to Caicedo in Europe's top five leagues. Both ferociously effective against the ball, the Japan captain has surprised many by also adding a great deal of value in possession, maintaining a high pass completion rate and even creating a steady stream of chances.

To all intents and purposes, Endo and Caicedo have performed the same role for the past 18 months, and performed it to a pretty identical standard.

Of course, Caicedo has many years ahead of him, while Endo is already in the later chapters of his career. But in many ways, the 31-year-old has already fulfilled his duty, acting as a bridge to accommodate the emergence of the new-look Liverpool midfield.

Because what makes the Caicedo affair look particularly hilarious in hindsight is the price for which Liverpool secured Mac Allister in the same summer. Also arriving from Brighton, the Reds took advantage of a release clause to sign the World Cup winner for just $44m (£35m).

At less than a third of the price, Mac Allister has been at least as effective as his former teammate, shining as one of the very best midfielders in the division. And alongside Szoboszlai and Gravenberch, who has been a revelation under Slot, the headline trio of 2023 have grown into the formidable engine room that Liverpool foresaw.

Caicedo is getting on fine. He must be, after all, to be keeping pace with Endo's numbers.

But while he fights for fourth, Liverpool is gunning for the title, and the Reds probably wouldn't swap any of the midfielders they signed that summer in exchange for Caicedo. That might well even include Endo, who has turned out to be exactly the right man at the right time.