Luiz is now long gone. But you can just imagine the headlines, the blame, the absolute abuse, if he was still pulling on a Blues shirt today. Three shipped in defeat to West Ham. Another three in the Sheffield United loss. And then this week, five at the new champions, Liverpool. That's not the stuff of a top four team - let alone a title challenger. Something isn't quite right at Chelsea.
For now, it seems we've concluded it's all down to individuals. Personnel. Kepa Arrizabalaga the first who must be bounced out the club. But how anyone blames the Spaniard for any of the five goals at Anfield is beyond this column. But in the present mood of Roman Abramovich, Chelsea's billionaire owner, it seems the answer is to simply throw money at it. And it doesn't just begin and end with the goalkeeper.
Frank Lampard is also seeking a new centre-half. Indeed, a new, young centre-half. He has Fikayo Tomori. Andreas Christensen. Even Marc Guehi, currently away on-loan with Swansea City. They've all shown promise. Potential. More than simply a suggestion they could develop into players of world-standing. But it seems that's not enough for Chelsea's manager.
Instead, Lampard has approved an approach to Red Bull Leipzig for Dayot Upamecano. And refused to shut down talk of bringing Declan Rice back to the club from West Ham.
"Declan Rice is a good player, you're right, and I've known Declan Rice for a long time, as he was in the Chelsea academy," said Lampard earlier this month, before hastening to add, "(But) until these games and this season is finished, there's nothing to say."
But you get the picture. It may not be Rice. Nor even Upamecano. But Lampard is seeking that type. A young centre-half, with good first team experience, who's best days are ahead of him. In other words, another Tomori or Christensen.
And that's just it. Will things suddenly click when Lampard swaps one young centre-half with another from outside? And what about the goalkeeper...?
In England, there's plenty doing the rounds about Dean Henderson, Sheffield United's on-loan No1 from Manchester United, and Burnley's England capped Nick Pope. But again, we're talking about promise here. Potential. Henderson is 23. Pope 28 - which is still relatively young in keeper circles. Will Chelsea simply be shuffling the deck chairs if this move goes ahead?
Perhaps the problems aren't personality-driven? Kepa still has his supporters - and admirers - in Spain. Christensen won't be short of offers from major rivals should he be made available. And there's hope inside the England setup that Tomori will be a genuine candidate for next summer's Euros squad. And all this admiration has been generated by what these individuals can develop into. Which, of course, is the same thinking that dominates discussion inside Cobham around Henderson, Upamecano and Rice.
So maybe it's time for Lampard to look deeper. To consider his staff. His own focused coaching. Is enough being done on the Cobham training pitch with his back four? Are those who make up his backroom team capable of improving individually and collectively their young, defensive players? Indeed, when we talk about individuals, is it time for Lampard to send out an SOS for a specialist defensive coach?
And that SOS doesn't need to be answered from outside. It could simply involve a promotion. Ashley Cole, Lampard's long-time Chelsea teammate, joined the academy coaching team this season, taking charge of the club's U15s. It was an appointment fully endorsed by Lampard, who had considered the former left-back for his senior panel.
He may lack coaching chops, but with his defensive background, his mountains of playing experience, Cole would offer a different perspective to Lampard's assistants Jody Morris and Joe Edwards.
Cole pulled apart Chelsea's back four for the defeat at West Ham at the beginning of the month. With 338 Blues games under his belt, Cole didn't miss. Toni Rudiger. Marcos Alonso. Christensen. They all were singled out by Cole on the night. But significantly, the club icon also stated: "As units, as players, you've got to want to work and not be happy to be beat.
"Things I hate about full-backs are that they're happy to run forward and not track.
"Yes, you're pushing. But first and foremost, you've got to defend."
Everything, as a defensive unit, Lampard must be seeking. Cole has used the TV studio to put forward his theories. In this period of his team's development, it's now time for Lampard to hand his old teammate the chance to put them into practice.