Chelsea's summer of chaos: World-record £450m spending spree leaves Mauricio Pochettino with near-impossible puzzle to solve

Chelsea's priority ahead of the transfer window was well-documented: get rid of every unwanted or unsettled player to trim down what had become a cripplingly bloated squad. That task has been completed unequivocally; no fewer than 26 players have departed, either permanently, on loan or at the end of their own temporary spells at Stamford Bridge.

Headlining that lengthy list are Kai Havertz, Mateo Kovacic and Mason Mount - all of whom completed big-money moves to Premier League rivals in Arsenal, Manchester City and Manchester United, respectively. As an academy product, Mount's £60m ($76m) fee represents 100 percent profit for the west Londoners.

However, although Chelsea finally managed to get rid of financial burdens Hakim Ziyech and Romelu Lukaku late in the window, the raft of incomings means the squad is still surely bigger than Pochettino would have liked with the 2023-24 campaign already underway and the Blues only involved in the domestic cup competitions. There are going to be some members of his playing staff who are left disappointed, and the vicious cycle could continue.

Although the player had evidently grown unhappy at Stamford Bridge, Mount's sale reflected Chelsea's determination to arrest a steep slide towards falling foul of Financial Fair Play regulations.

The club has raised around £200m ($254m) from player sales, with the individual fees registered in the year's accounts in full and immediately - unlike their amortised incoming transfers, with significant fees broken down as they are spread across the years of unusually long contracts.

Although that figure may seem like it comes nowhere close to offsetting the eye-watering sum Boehly and Eghbali have spent in the past year or so, the ~£100m ($127m) raised through the sales of Havertz, Mount and Kovacic alone could theoretically fund £500m ($636m) in transfer fees amortised over five-year contracts, per The Athletic.

On paper, letting Mount leave and then signing a player with a similar profile in Man City's Cole Palmer for £42m ($53m) seemed nonsensical, but in all likelihood it was mainly financially motivated. Cobham prospect Lewis Hall has also been allowed to depart for Newcastle on an initial loan, with an obligation to buy in a year's time.

It has been a bewildering summer of transfer business, and deals like this will leave a sour taste for fans who want to see academy stars shining in the first team.

Despite their willingness to get rid of their own, Chelsea's quest to recruit the world's brightest young stars has continued apace, with each of their 11 summer signings aged 25 or under.

Away from the bigger names, the Blues have spent a further £50m ($63m) on teenagers Lesley Ugochukwu, Deivid Washington and Angelo, while Diego Moreira has joined on a free transfer from Benfica.

However, for the time being only Ugochukwu seems to have a place in the first-team squad for the 2023-24 season, and on the early evidence there are serious question marks over whether any of them will make a breakthrough or simply be seen as investments in a quasi-Moneyball approach to the transfer market.

Two of those young signings were at the centre of an epic transfer saga that could have a huge bearing on the long-term future of Chelsea's midfield, an area that had been earmarked for a summer overhaul following the departures of Kovacic, N'Golo Kante, Ruben Loftus-Cheek and Jorginho over the past two windows.

Brighton's Moises Caicedo was the No.1 target across the summer, but negotiations were laboured as the London club tried to negotiate down the Seagulls' firm £100m ($126m) valuation. Then, a remarkable Friday in mid-August almost saw Chelsea lose out on the 21-year-old to Liverpool, but the player's preference saw them seal a British-record £115m ($145m) deal.

In an even more extraordinary turn of events, and to rub salt into Liverpool's wounds, the Blues then snatched Southampton's Romeo Lavia - who the Reds had turned to as an alternative - from under their noses to transform their midfield in the space of four days.

The combined £173m ($218m) fee for the defensive-midfield duo quite simply beggars belief, but Chelsea could not afford to miss out so dramatically on their two priority targets for an area of the pitch that was in dire need of high-quality reinforcement. If all goes to plan, aged 21 and 19 respectively, Caicedo and Lavia can be the linchpins of the team for years to come.

Chelsea's most significant signing of the summer was supposed to be RB Leipzig's goal-contribution machine, Christopher Nkunku. However, the Blues were shorn of their new star attacker before a ball was kicked in competitive action as he suffered a serious knee injury on a questionable pitch in pre-season.

That followed Wesley Fofana's ACL rupture and preceded a hamstring injury for newly-named captain Reece James. Carney Chukwuemeka has also suffered a knee problem of his own and undergone surgery.

Those injuries, and especially the one to potential difference-maker Nkunku, have taken the gloss off Chelsea's transfer business. Indeed, there will be a sense of incompleteness until the Frenchman returns, and they will never be at full strength without skipper James. Palmer represents an expensive contingency plan in attack, but he is unproven as a regular starter.

As it stands, it's unclear what Pochettino's best team is, what formation he will deploy long-term and who fits best where. With the window now shut, the Argentine tactician will have to make do with what he's got for the time being as he waits for those key players to return.

Palmer's arrival took Chelsea's spending to a world-record £448.5m ($565m) for a single transfer window - although that is offset by that £200m raised in player sales - and past the £1 billion ($1.26bn) mark under their new ownership.

Injuries and grossly inflated transfer fees aside, Chelsea have unquestionably achieved what they set out to when the window first opened - ridding themselves of expendable players, reinforcing the midfield and bringing the wage bill down.

However, the unprecedented upheaval has resulted in a sense of chaos, incompleteness and unfamiliarity, with Pochettino left to piece together a team that is capable of winning games regularly to shake off the residual malaise of a nightmarish 2022-23 campaign.

Chelsea have spent a world-record sum in this window, but in truth they do not look that much closer to the finished article, and there is little doubt that there will be more significant spending to come in the near future - namely on an elite goalkeeper and striker.

It remains to be seen what Pochettino can achieve this season, but his main priority now will be to get this new-look, incredibly expensively-assembled squad to gel as quickly as possible.