Watching Frank Lampard's Chelsea play football has been a real rollercoater. They have played some of the most exhilarating attacking football in the world, but combined that with some utterly shambolic defending.
On any given day, the Blues could ship four or five goals (even though they might score just as many at the other end). While it makes for enthralling watching, it's obviously not the most sustainable way to play football.
A lot of blame has been thrown at goalkeeper Kepa Arrizabalaga, who has undoubtedly underperformed this year, but the truth is that he hasn't been helped out by his centre-backs.
Antonio Rüdiger, Andreas Christensen, Fikayo Tomori and Kurt Zouma have all struggled at times and left their goalkeeper exposed, and that's why the Blues have been chasing a big-money signing to bolster their defence.
Back in March, 90min revealed that Chelsea are interested in Napoli's Kalidou Koulibaly, who would be the perfect man to solve Lampard's defensive woes.
The boss' youth revolution has added some real flair to the team, but a consequence of getting younger is reducing the top-flight experience in the team. Chelsea seem to have plenty of mistakes in them, and given they're competing in the Champions League, that's not good.
Against top competition like Bayern Munich, Chelsea were comprehensively thumped 3-0, proving that there is still a long way to go before the Blues get to where they want to be. They could choose to wait and gamble on their young squad getting better with age, or they could speed the process up and recruit Koulibaly.
The Senegal international, who will turn 29 in June, comes with six years of Serie A experience and has been a focal point of Napoli's title charges every year, so there's no doubting his talent. But what makes Koulibaly so perfect for Chelsea is just how well he would fit in at Stamford Bridge.
As a ball-playing centre-back who is dominant both aerially and on the ground, he is everything that Lampard wants in a defender. Koulibaly can kick-start attacks with his long passing but is equally as comfortable finding Jorginho with a shorter pass - a technique which worked flawlessly for Napoli in the 2017/18 season.
Alongside his natural creativity, Koulibaly comes with a unique blend of agility and physicality which would work perfectly in the Premier League. It's a similar style to Liverpool's Virgil van Dijk, who is arguably the finest centre-back around these days.
Not only does Koulibaly play like Van Dijk, but he could have the same influence on the pitch as the Dutchman.
Before Van Dijk joined Liverpool, Dejan Lovren and Joël Matip were only good enough to lead Liverpool to fourth, yet playing alongside someone with Van Dijk's leadership and intelligence has made both better (even if Lovren has gone back to his catastrophic self).
His influence would rub off on every member of Chelsea's young squad, but his impact would be felt most by both Christensen and Tomori, who are still young and inexperienced enough to be learning the ropes in the Premier League.
In terms of which player would play alongside Koulibaly, there are a few good options. Rüdiger is perhaps Chelsea's best defender right now (when he actually shows up), but Christensen could be the perfect complementary piece alongside Koulibaly.
The Dane's positional awareness and technical ability would blossom next to Koulibaly, whose physicality would more than make up for Christensen's slender frame. The pair would have it all.
Not only is that a defence which can keep more than the six clean sheets which the Blues have managed this year, but it's a defence which could aim far higher. With the right additions elsewhere, competing for a league title might become possible once more.
Source : 90min