The Blues travelled around the US and played a gruelling five matches in five states in 18 days, winning once, drawing once, losing three times and conceding 12 goals.
Here are seven talking points from a tour that has taken Chelsea from Santa Clara to Charlotte.
1. An unchanged transfer approach?
Chelsea have not lost confidence in their youth-first approach despite two underwhelming years under the new Todd Boehly-Clearlake ownership, which has seen them fail to qualify for Europe in the first season, and only qualify for the Uefa Conference League in a second, improved season.
The Blues have spent about £115m on eight players with an average age of under 21 – Kiernan Dewsbury-Hall, Tosin Adarabioyo, Estevao Willian, Marc Guiu, Filip Jorgensen, Renato Veiga, Omari Kellyman and Caleb Wiley.
That average could go even younger as Chelsea are expected to sign 18-year-old goalkeeper Mike Penders from Gento and 20-year-old striker Samu Omorodion from Atletico Madrid.
In terms of big name signings, there is also interest in Napoli striker Victor Osimhen, who could be involved in a swap arrangement with Romelu Lukaku.
Social media graphics of their 45-man senior squad, external – which includes seven registered goalkeepers – have gained traction this week.
But there remains a belief inside Chelsea that – despite widespread criticism of the club’s transfer activity – this approach will ultimately reap rewards for Chelsea, BlueCo as a whole, and RC Strasbourg who are part of the multi-club group.
2. Chelsea’s change of style
Chelsea are set to implement a new, slower and possession-based style of football under Enzo Maresca.
This has already been apparent in the club’s pre-season tour of the US and it demands players adapt to the manager’s approach, rather than him adapt to his players.
It has meant teams on tour, like Manchester City and Celtic, have been able to force mistakes as players struggle to adapt to high-risk moves playing out from the back.
In fact, half the 12 goals conceded in pre-season were from mistakes playing out from the back, including three of the four against City.
There are also problems with the players naturally defaulting to a high defensive line without pressing well or with intensity, a feature of the play Maresca blames on “habit from last year”.
Other features of the tactics are underlapping full-backs, man-to-man marking and two very high number eights occupying spaces in a five-man attack.
The high risk, high reward style carries the same core principles evident in the Italian’s Championship title-winning Leicester team last season.
Interestingly, these principles are supposed to be implemented across the club and into BlueCo with RC Strasbourg – maintained even if there is a need to change the manager again in the future.
One of the reasons Mauricio Pochettino left by mutual consent was due to a difference in opinion on the club’s long-term tactical identity.
3. Nkunku set to become Chelsea’s key man
Christopher Nkunku has played 398 minutes, more than any other player during the tour and looks set to have a starring role this season – if he can stay fit.
Like last summer, the Frenchman again excelled in pre-season and netted three goals in five matches on tour, playing in several different positions, including as a striker and central midfielder.
Last summer, Nkunku suffered a knee injury in the final match, which began a chain of different injuries to limit him to just two starts last season.
Nkunku said he wants to stay fit first and see where his football takes him, admitting that he is still “not 100%”.
But Maresca clearly likes the versatile star and said: “Christopher [Nkunku] was injured for almost all of last season but I knew from Germany how good he is. He has surprised me but it is not a big [surprise].”
4. Too many matches and too much travel?
Maresca was asked by BBC Sport whether the tour schedule was optimal preparation and he said: “Five games in [14 days] and 17 or 18 days in total is a lot.
“We didn’t prepare the games with the training session like we are used to doing during a normal season. Some of the games, we just prepared with a video or the tactical board.
“For me, the real pre-season has been the two weeks at Cobham and the week or 10 days we have [next]. Here, it has been a mixed feeling.”
Midfielder Moises Caicedo also joined Maresca in criticising some of the pitches they played on in the US as “not so good” and “so dry”.
At least this summer Chelsea avoided picking up any injuries while on tour.
5. Reece James or Malo Gusto as full-backs become talking point
Malo Gusto will begin the season at right-back as Reece James serves a three-match ban in the Premier League for a red card sustained in the penultimate match of last season.
But James and Gusto will have to co-exist and both, at times, have struggled to adapt to the demands of being a full-back for Maresca.
In Maresca’s system, one full-back typically becomes inverted and steps into central midfield and the other sits back to defend as a third central defender, which turns a back four into a back three.
James should be capable of performing either role but has struggled as he also builds fitness after an injury-hit season.
Gusto has also struggled and has played a left-back three times, with Levi Colwill also tried out in the role as Marc Cucurella recovers from Euro 2024.
Maresca has admitted that some of his unusual team selections have come as he looks to “experiment” in pre-season, but left-back Ben Chilwell has played just 64 minutes and in two matches from the bench, raising new questions about whether he could be sold.
The addition of new goalkeeper Jorgensen from Villarreal is also interesting as the Blues wanted a specialist at playing out from the back to compete with Robert Sanchez, but it has left Djordje Petrovic likely to be pushed out of the club, at least in the short-term on loan.
The atmosphere around the squad seemed broadly positive under Maresca but such is the pace of signings, representatives around several players admit uncertainty around their futures left them feeling insecure.
6. Fernandez and Gallagher make headlines
The two controversial subject of pre-season have been around midfielders Enzo Fernandez and Conor Gallagher.
Fernandez faces no further action after an internal investigation at Chelsea, but continues to be investigated by Fifa, having been accused of being racist for singing an offensive song after winning the Copa America.
The ongoing Fifa investigation could still lead to a significant domestic ban.
A meeting in Atlanta with the French players affected – including defender Wesley Fofana who had criticised Fernandez publicly – is said to have gone well, with Maresca saying the players had “all accepted” Fernandez’s apology, allowing Chelsea to re-integrate their £107m signing into the squad.
Fernandez will likely be targeted by boos from fans of other clubs next season but there is little chance of him leaving Stamford Bridge – and he was made captain against Real Madrid after Reece James was substituted.
Gallagher, meanwhile, wasn’t involved in Chelsea’s pre-season having been given a break after Euro 2024.
But Gallagher’s potential sale to Atletico Madrid was a major talking point among supporters, many of whom seemed upset to lose another homegrown star.
7. What is the target for Maresca’s first season?
The hiring and firing of managers that characterised Chelsea’s previous ownership under Roman Abramovich hasn’t changed under their American consortium.
Real Madrid manager Carlo Ancelotti urged his former club to show patience with Maresca when interviewed by BBC Sport before the two sides met in Chelsea’s final pre-season.
Chelsea have belief that Maresca can stop that cycle, evidenced by his five-year deal, compared to the two-year deal given to Pochettino last summer.
There is an expectation that Chelsea should be able to qualify for the Champions League, given they only fell short by six points last season amid huge injury problems.
There will be some leeway if Maresca doesn’t hit that target but can show progress in other areas like winning cup competitions, developing players or if mitigating circumstances, like injuries, again become a major factor.
Chelsea are minded to be patient but that’s not a word the club has been known for.
