Had it not been for the midfielder's departure to Barcelona, the likes of Virgil van Dijk, Alisson and Fabinho may not have been subsequently snapped up, the trio all proving pivotal to securing Premier League and Champions League honours under Klopp's watch.

He was a gem of a player in his own right, it must be said, although as a pure business deal, they don't get much better than Liverpool's capture of a 20-year-old Coutinho.

How much Liverpool paid to sign Coutinho

Everything really came together under FSG's watch with the enigmatic figure of Klopp at the helm, although that's not to say transfer success stories didn't also occur prior to that.

January 2013 sticks out as a particularly fruitful window for then-boss Brendan Rodgers, the Northern Irishman putting the foundations in place for the surprise title charge the following season.

In came Daniel Sturridge from Chelsea, as did a promising playmaker by the name of Coutinho, the rising Inter Milan star snapped up for a relative bargain fee of just £8.5m.

The youngster had only made 47 appearances in Italy by that stage, yet Liverpool had clearly seen enough to be encouraged by, this slight, diminutive talent looking like a real superstar in the making.

The rest, as they say, is history.

Why Coutinho remains FSG's best piece of business

While not part of Klopp's title-winning side in 2019/20, Coutinho was a central figure in the team that so nearly ended the drought in 2013/14, memorably netting that goal against title rivals Manchester City.

That year was all about Suarez, yet a star emerged too in the form of his South American counterpart, Coutinho scoring and assisting ten league goals that year.

That was a record he matched the following year, while by 2016/17, he'd really cemented his status as Anfield's main man, registering 20 goal involvements in the top-flight.

For a brief time, the Reds got to witness the midfielder in action alongside the likes of Roberto Firmino, Sadio Mane and Mohamed Salah in 2017/18, yet the pull of Barcelona proved too much heading into that January window.

Having handed in a transfer request over the summer, Coutinho finally got his wish, with Liverpool tempted into a mid-season sale after receiving an eye-watering £142m offer from the Catalan side.

Considering the bargain nature of his initial cost, there can't be too many better examples of a piece of transfer business out there anywhere, with such a sale proving a real sliding-doors moment, be it for Coutinho, Liverpool or for a later cash-strapped Barcelona.

What an astute signing he proved to be for the Reds, with it looking like FSG might have repeated the trick in recent years.

Why Liverpool starlet could be another Coutinho in the making

At a time when the Merseysiders have spent big on the likes of Alexander Isak, Florian Wirtz and Bradley Barcola, low-cost signings have been few and far between at Anfield.

It's in the academy ranks where the club have had greater success in that regard, notably plucking Rio Ngumoha from Chelsea for an initial fee of around £3m, while also snapping this season's breakout star, Trey Nyoni, for a similar bargain price back in 2013.

Indeed, as reported at the time, the Reds paid around £1m to prise the 16-year-old from Leicester City, a handsome for a mere teenager, yet a minimal fee in terms of the usual senior signings made.

It's taken time for Nyoni to really force his way into the club's first-team plans on a permanent basis, although he looks set to be Andoni Iraola's latest pet project, the Spaniard previously overseeing the rise of the likes of Eli Junior Kroupi and Rayan back at Bournemouth.

Still only 19, the teenage Englishman is already earning rave reviews amid his involvement in the early weeks of the new campaign, having been hailed as Liverpool's "best player in pre-season" by U21 coach, Jay Spearing.

He notably started and starred in Liverpool's 3-1 win over Tottenham Hotspur in the Carabao Cup, with it having been rather telling that the hosts lost all sense of control once the youngster had been withdrawn late on.

While a more deep-lying option than Coutinho, Nyoni is another highly technical, progressive talent, already someone who, like the Brazilian before him, looks ready to be a central figure in the starting lineup at such a young age.

The Reds won't exactly be thinking about selling him any time soon, but considering that £1m price tag, they do look set to make a significant profit later down the line if an exit is to occur.

He's only made 24 first-team appearances, yet his value has risen by around 600% so far, with Transfermarkt deeming his current worth to be roughly €8m (£7m).

That's already a healthy increase in a relatively short space of time, with this looking set to be another deal that goes down as one of FSG's best pieces of bargain business.

Will anything ever beat Coutinho, however?