It took spending £75m on Virgil van Dijk for Jurgen Klopp to solve a Liverpool problem position that had troubled the German and his predecessors for far too long.

From the imperious partnership of Sami Hyypia and Stephane Henchoz that was so crucial to Gerard Houllier’s treble-winners to Jamie Carragher cementing Reds legendary status in Istanbul, the heart of the Reds defence was rarely an issue in the noughties with Rafa Benitez adding Daniel Agger and Martin Skrtel as the decade wore on.

However, as the ill-fated ownership of Tom Hicks and George Gillett prompted a Liverpool decline, coinciding with father time catching up on Carragher, holes began to emerge as what had once been a Reds strength swiftly became a weakness.

Restricted by budget constraints under the infamous American owners, Benitez was forced to turn to Sotirios Kyrgiakos to strengthen his pack in the summer of 2009, while Roy Hodgson and Kenny Dalglish brought in Danny Wilson and Sebastian Coates with the duo unable to make their mark.

But it was under Brendan Rodgers where Liverpool’s defensive woes were highlighted most once Carragher called time on his Reds career following an Indian summer after two seasons in reserve.

Yet the answer could have been under his nose the whole time. And cost him a lot less than he ended up spending.

In the summer of 2013, just months after making his senior debut, a 20-year-old Conor Coady was sent on loan to League One Sheffield United as Rodgers opted to reshuffle his senior defensive ranks rather than promote from within.

Kolo Toure was signed on a free transfer before Mamadou Sakho and Tiago Ilori were signed on deadline day for £18m and £7m respectively.

Liverpool agonisingly missed out on the Premier League title that season, and while their charge was led by the attacking prowess of Luis Suarez, Daniel Sturridge, Raheem Sterling and Philippe Coutinho, it was their defensive softness that would prove to be their Achilles’ heel.

Everyone remembers Steven Gerrard’s infamous slip against Chelsea as the Reds conceded a lead at the top of the table at the final straight of the title battle, but it was their leaky defence that ultimately cost them despite the previous summer’s recruitments as they conceded a staggering 50 goals.

In contrast, Coady enjoyed a memorable season with the Blades, making 50 appearances as they narrowly missed out on the play-off places but reached the FA Cup semi-finals against the odds.

Of the defensive trio signed that summer, Toure made the biggest impact while the Sakho’s Anfield career was shrouded in controversy before belatedly being moved on by Klopp.

As for Ilori, born just the day after Coady, he never made a Premier League appearance for the club and now finds himself back in Portugal after a number of unsuccessful loan spells and underwhelming permanent move to Reading.

In hindsight, Rodgers would have been better to turn the Scouser. Instead, he continued to spend and parted with another £20m to sign Dejan Lovren in the summer of 2014.

Meanwhile, Coady was sold to Huddersfield Town for just £500k before signing for Wolverhampton Wanderers in a £2m deal the following summer.

Liverpool’s defensive woes continued and eventually cost Rodgers his job.

As such, it wasn’t until Klopp’s arrival that the Reds really began to rectify such issues.

Swiftly moving on the likes of Sakho and Ilori, Steven Caulker and Ragnar Klavan offered stop-gaps alongside the successes of Joel Matip and Van Dijk, while the German has also overseen the best from one of Rodgers’ last signings, Joe Gomez.

While defensive flops contributed to the former Liverpool boss’ Reds exit, his biggest oversight has ultimately been highlighted by Coady’s rise since moving to Molineux in 2015.

A key player as soon as he arrived in the West Midlands, he was implemented as a middle centre-back in a defensive three by new boss Nuno Espirito Santo for the 2017/18 season and hasn’t looked back since.

Captaining Wolves to the Championship title that year, missing just one game, he was handed the armband permanently following their promotion to the top-flight and has been an ever-present in the top-flight in the past two seasons.

Qualifying for Europe in their first year back in the Premier League, Coady led his side to the Europa League quarter-finals last season with the 27-year-old’s consistent form belatedly rewarded with a deserved, maiden England call-up by Gareth Southgate for Nations League clashes with Iceland and Denmark next month.

Whether he would have reached such heights at Anfield is impossible to say and while Klopp ultimately solved Rodgers’ problem position, it took spending £75m on Van Dijk.

For all the money spent on expensive defensive failures over the years prior to the Dutchman’s arrival, the Reds only banked £500k for a man that has emerged as one of the Premier League’s most impressive defenders.

As Coady prepares for a potential England debut, Liverpool find themselves short in defence once again after Lovren’s move to Zenit St. Petersburg and pondering whether a new recruit is needed.

And regardless of whether Klopp does opt to add to his ranks, for Reds bosses the Wolves skipper remains one that got away.