Chelsea slipped to a 1-2 defeat against reigning Premier League champions Arsenal on Sunday evening, in a contest that raised a major question mark over the depth of their options in midfield.
By the final whistle, Chelsea had two players who both began their careers at right-back, Reece James and Malo Gusto, lining up alongside each other in midfield. How did a club that spent 349 million pounds during the summer transfer window end up here?
James was handed the job of marking Arsenal captain Martin Odegaard, but he failed to deal with the Norwegian during the passage of play from which Odegaard scored the winning goal for the hosts at the Emirates Stadium.
Chelsea manager Xabi Alonso had praised James's abilities before the match, insisting the Englishman had the potential to become one of the best midfielders in the world, according to BBC Sport.
Aside from the goal, James delivered a generally good performance, especially as he spent almost half of last season playing in midfield. The way he was used, though, reflects legitimate questions about the depth of Chelsea's options in this position, particularly after Alonso brought on Gusto instead of midfielder Romeo Lavia during the second half.
Arteta's substitutions reveal the difference
Slack marking gifted Odegaard his goal, but the problem did not stop at the defensive side. Chelsea looked short of creative solutions on the bench.
Arsenal, by contrast, had options more capable of changing the shape of the match, and Mikel Arteta made the most of his substitutions perfectly, ultimately leading his team to settle the contest.
Ashley Young told BBC Sport: "Chelsea are not competing in European competitions this season, so they play fewer matches and can focus more on the Premier League. But the cause for concern is that they end a match against the reigning champions with two right-backs in midfield."
He added: "Look at Lavia, who suffered a lot from injuries last season. The attacking line will frighten many teams in the league, but behind it we find the midfield, where two right-backs are being deployed."
He continued: "Other teams will watch today's match, and they will notice that Chelsea rely on defensive compactness and putting as many players as possible behind the ball, yet there are still spaces between the lines, and that is what Arsenal exploited."
He went on: "Chelsea concede possession a lot and rely on counter-attacks. Today, there was perhaps only one chance, through Pedro Neto on the right side, during which they succeeded in exploiting a counter-attack."
Why is Chelsea suffering a midfield crisis?
The most prominent problem Chelsea currently face is the absence of Ecuadorian midfielder Moises Caicedo.
Nobody has disclosed the nature of the injury, and no return date has been set, after Caicedo picked up the problem following an 11-minute cameo as a substitute against Brighton last week.
His absence has put Alonso in an unusual position. Apart from suspensions, Caicedo has missed only two matches over the past three seasons, due to a minor injury and an illness.
Asked about Caicedo's condition, Alonso said: "It is not about a long-term absence, but about risk assessment. We may have brought him back to play too early last week, and I do not want to repeat the same mistake."
Whether Caicedo's injury prompted Chelsea to intensify their efforts to sign a new midfielder on the final day of the transfer window remains unclear.
Chelsea tried, but the deals faltered
Chelsea did indeed seek to strengthen their midfield in the final hours of the transfer market, but they could not complete a single deal.
Monaco aborted Chelsea's attempt to sign Lamine Camara for 47 million pounds at the last moment, and the collapse of the deal angered officials at the London club.
Bournemouth also rejected Chelsea's offers, which reached 64 million pounds, to sign Alex Scott earlier in the summer.
Meanwhile, the attempt to sign Frenchman Manu Kone faltered after Roma manager Gian Piero Gasperini obstructed the player's move.
Chelsea explained that the move for Camara came as part of taking advantage of an available opportunity in the transfer market, stressing their satisfaction with their summer deals and their confidence in the current group.
Enzo Fernandez's departure added to the question marks
Questions about Chelsea's midfield options grew after the club sold Enzo Fernandez to Manchester City for 125 million pounds, a figure equal to the British record, on the final day of the transfer window, without signing a direct replacement.
Right now, Caicedo joins Jordan Henderson on the injury list. The England international is still recovering from a broken arm he suffered after falling onto an advertising board, while sitting on the bench without playing for his country's national team at the World Cup.
Valentin Barco, a natural midfielder who joined from Strasbourg during the summer, has not featured either, as Alonso preferred to field Gusto in all three of the team's Premier League matches.
A historic figure reveals the possession problem
The shortage in midfield options showed clearly during the Brighton match last week. With Gusto playing in midfield, Chelsea had possession only 25.6% of the time in a contest that ended 4-3 in their favour, the lowest possession figure for the club since this data began to be recorded in the 2003-2004 season.
If every midfield player is available, though, and Caicedo's injury proves not to be serious, Chelsea should have enough options to handle the season, particularly given their non-participation in European competitions and the resulting absence of midweek matches.
Alonso had pointed to exactly this before the Arsenal match, insisting his team has enough numbers in midfield.
The attack rescues Chelsea, but the defence worries Alonso
Across their first three Premier League matches, Chelsea have leaned heavily on their attacking strength, amid the brilliance of Morgan Rogers, Cole Palmer's return to form, and the scoring effectiveness of Joao Pedro.
Rogers, who joined Chelsea in a record deal, scored again in the second minute against Arsenal, becoming the first Chelsea player to score or assist in each of the team's first three league matches in a single season since Eden Hazard in the 2018-2019 season.
Chelsea have also conceded seven goals in those first three matches, which prompted Alonso to stress the need to improve defensively.
The Spanish coach said: "We want to be more cohesive and solid defensively." Despite the defeat, there was much to praise in Chelsea's performance against Arsenal. It ranks as one of Chelsea's best matches against their London neighbours during a run that extended to 10 consecutive matches without a win over them.
The gap between the two teams remains large, though. Chelsea need to make up 33 points, after finishing last season tenth in the Premier League.
Alonso said after the match: "We came to win. We knew we were not far off them in terms of level, but the match went their way, it is painful, and we certainly feel disappointed, but this is the first defeat, the journey is still long, and it will not greatly affect our morale or our mentality."
Arsenal set the standard, and Chelsea face a new test
Arsenal remain the standard Chelsea are chasing. Despite beating their London rivals in the race to sign Rogers, the team still lag behind the club that sets the benchmark for competition at the top in London and the Premier League.
Sunday's contest showed that Chelsea's huge spending has not solved every problem. Despite signing 10 first-team players during a busy summer, the failure to sign a midfielder on the final day of the window may have left a clear gap in Alonso's squad.
Alonso had described the summer transfer window as "the first stage" in his project with Chelsea. The real test now will be the team's ability to overcome this problem.
Should Caicedo's return fail to resolve the midfield crisis, Chelsea may find themselves facing mounting questions about the decision not to sign a direct replacement for Enzo Fernandez, before heading back into the transfer market in January.