Chelsea crashed out of the FA Cup at the first opportunity against Manchester City on Sunday afternoon, on the end of a 4-0 clobbering at the Etihad Stadium.

If Pep Guardiola’s City represent a fortified stronghold, Graham Potter’s Chelsea are nothing more than a dilapidated ruin; six losses from the Blues’ past eight matches across domestic competitions, Stamford Bridge is in danger of hosting a truly woeful campaign if requisite adjustments cannot be swiftly made.

The disparity between the two outfits is great, with City on course for another resounding season, fighting for major silverware on every possible front, and Chelsea languishing in tenth place in the Premier League, also defeated in both domestic competitions, both at the hands of the Sky Blues.

Injuries have played their part in the west London club’s downfall this term, but there is no excusing the manner in which Chelsea surrendered the tie, the levels in which City roared several octanes above their opposition.

At the epicentre of the defeat was Kalidou Koulibaly, summer signing of £33m from prominent Serie A outfit Napoli, who has thus far been on the end of scathing criticism over his standards on English soil with regularity.

Granted, Kepa Arrizabalaga was woeful in between the sticks, recording a match number of 5.9, as per Sofascore, but it was the Senegalese titan that once again failed to stamp his authority on proceedings, failed to display the assurance and defensive might that left fans and pundits alike waxing lyrical over his skill-set while plying his trade in Italy.

In a back-four containing the inexperienced Lewis Hall and Bashir Humphreys, it was the 30-year-old ace illuminated for his substandard showing, bypassed with ease by the fluid, cohesive City offence.

Recording a match-worst rating of 5.8, Koulibaly failed to make a single tackle - despite City finding space to unleash seven shots on target - and also conceded one of the two penalties that the home side buried into the net.

Losing possession 14 times, he only won one of his four total duels and could only complete 54 passes at an accuracy rate of 78% - despite having 75 touches in total.

Chelsea writer Jai McIntosh was particularly dismayed by his dreadful display, saying “Koulibaly can’t defend"; words that would hit the African ace hard considering the reputation he has forged for himself over the majority of his professional career.

The £160k-per-week star has also only recorded an average Premier League rating of 7.03 this term, far lower than the veteran Thiago Silva’s 7.31, and if he cannot combine the cogs and demonstrate why he earns a regular place in the side for the new Chelsea project, moves must be made to replace the beleaguered centre-back, despite his recent arrival at Stamford Bridge.