Chelsea may well be reigning Premier League champions, but Antonio Conte's side have a massive fight on their hands if they're to retain that status this season.
It hints at some cracks in Conte's formula as the Italian attempts to build on a successful debut campaign.
Still, it's not all doom and gloom at Stamford Bridge. Despite missing out on some high-profile transfer targets this summer, Chelsea have strengthened their squad in key areas and look better equipped than they did this time last year.
The fears of a repeat of their title defence in 2015/16 have long since passed, and they have a platform to kick on and challenge when the October international break ends.
Here we look at how Conte's squad is coming together in the first couple of months of 2017/18. Who are the players who have really set down a marker for the season? Who are those who need to pull their socks up and contribute more?
Chelsea have played just once in the Carabao Cup, so we haven't included those players from the 5-1 win over Nottingham Forest. That means Ethan Ampadu, Willy Caballero, Jake Clarke-Salter, Kenedy and Dujon Sterling do not feature in our power rankings.
Charly Musonda and Davide Zappacosta have only appeared as subs in the Premier League on one occasion, while the latter has made just one appearance in the Champions League. Like those above, they haven't featured enough to earn a ranking.
New signing Danny Drinkwater remains on the treatment table and yet to make his debut. Jeremie Boga, who featured against Burnley, is now at Birmingham City on loan.
16. Michy Bathsuayi
How do you solve a problem like Batshuayi? It's complicated, as the Belgian has shown he can make an impact from the bench, yet equally, his presence means Chelsea can only play one way.
Does Conte trust him? The answer seems to be no at this stage, especially when Alvaro Morata went off injured against City and it was Willian who came on as his replacement, not Batshuayi.
He has a good social media game, but despite that winner against Ateltico Madrid, it's still not happening for Batshuayi on the pitch. He has to offer Chelsea a lot more than he is right now.
It's difficult to split Willian and Pedro right now as the pair have suffered with Conte's change of tactics and systems this season. We're not seeing the 3-4-3 every week now, instead a 3-5-2 (or 3-5-1-1 depending on preference) has been a big feature.
That means just one attacking midfielder to support the striker, so the pair have been rotated. Not only that, they're being asked to play different roles to what they're used to.
It's impacted performances. Willian's showing off the bench against City was abject, and from being a strong squad player, his position has been weakened.
For Pedro, read Willian. The Spaniard has also had to contend with injuries this term, which hasn't helped him build momentum. He edges Willian here because, for his dip in form, he has still scored twice in the Premier League and Champions League.
Chelsea need the Pedro of 2016/17, as without him on form, they lack the creative edge that won them big games last year.
13. Thibaut Courtois
As a goalkeeper, it's hard to fault Courtois. He's a class act when it comes to defending his goal and keeping opponents out. But ask him to play football and he struggles. We saw that last year, and this season it's continued.
Teams press Chelsea on their own penalty box when they have goal kicks, and Courtois' decision-making isn't always the best. It's a side of his game that he really needs to work on as his style seems to be becoming dated.
12. Victor Moses
When Moses was benched against City for the 1-0 defeat at Stamford Bridge heading into the international break, it didn't bode well for how Conte rates his defensive capabilities. The manager was wary of City's threat on the flanks, and he didn't want to risk it with Moses on the pitch.
In the long term, that hints at Chelsea needing an upgrade. If Moses can't be trusted in the biggest games, Conte needs to find a wing-back that can be.
Still, without Moses, it proved a bad decision from the manager. Chelsea missed his penetration in attack as Cesar Azpilicueta isn't capable of producing in the same way.
11. Andreas Christensen
Chelsea fans have been desperate to see an academy graduate step up to the first team and make a proper fist of challenging for a starting place. Well, they've finally got it with Christensen, whose performances this season have shown he's more than capable.
His problem is that he has some big names ahead of him, notably David Luiz. Still, Christensen has strengthened Chelsea's rearguard beyond all expectations, saving the club millions in the transfer market.
The Dane has looked assured and confident, hardly putting a foot wrong. Expect his power ranking to only strengthen as the season progresses.
10. Antonio Rudiger
Another defender who has turned heads this term is Rudiger, and Gary Cahill will feel him breathing down his neck, chasing a starting place. Rudiger's early form has shown him to be much more than a back-up, providing a solid alternative on the left or right side of defence.
He still has to earn his stripes with Conte, evidently. The manager dropped him for one of biggest games of the season against Atletico, preferring Cahill instead. But with Christensen and Rudiger in the squad, the Chelsea defence looks stronger than it has in a long while.
Fabregas is a luxury, and there's an element of him having to be indulged with the presence of Tiemoue Bakayoko and N'Golo Kante. But when on form, there isn't another player capable of doing what he does from midfield for Chelsea.
He's a big part of the five-man midfield working for Conte, like it did against Atletico. He has the style to complement the substance, and as his understanding with Morata grows, it could be an exciting addition to Chelsea's threat.
When it comes to the 3-4-3, though, Fabregas has problems and is far from ideal.
8. David Luiz
In the opening weeks of 2017/18, Luiz would have been higher than this. But since then he's earned himself a totally avoidable red card against Arsenal and gave away a poor penalty against Atletico that could've cost his team.
Last season reminded us of his quality, yet more recently the Brazilian seems to have slipped back into old erratic ways. Keep that up and Christensen won't just be knocking on the door, he'll be walking through it.
7. Gary Cahill
Where Luiz's discipline has let him down more recently, Cahill's has allowed him to get back on track this season. He started in the worst possible way with a deserved red card against Burnley, but he has put in some captain's performances since his return, learning his lessons.
Conte may well have been regretting giving him the armband permanently now John Terry has gone. The red card was a low point, although Cahill now looks every bit the captain he was last year. He was a rock against Atletico and a big reason for a historic win in Madrid.
6. Tiemoue Bakayoko
If this is Bakayoko still attempting to reach peak fitness, we're excited to think of how good he is going to be when he is 100 per cent. The Frenchman has been excellent since joining from Monaco this summer. From his debut against Tottenham Hotspur, he has the look of a player who can compete in English football.
He has some issues with spatial awareness and wanting too much time on the ball, but that will improve. And when it does, Chelsea's midfield partnership of him and N'Golo Kante is going to be formidable.
His physicality really is something to marvel.
5. Marcos Alonso
Eyebrows will be raised for Alonso featuring so high here, but these are power rankings after all. And despite being the only left-sided wing-back at the club, there's an argument to suggest he would be starting every week were the situation different.
The Spaniard gives Chelsea so much going forward, which is vital in that wing-back role. Not only that, he is a goal threat, as Spurs found to their detriment when he bagged a match-winning brace at Wembley.
Alonso isn't a master of defence or attack, but he comes with enough in both departments, which is what a wing-back is all about.
4. Cesar Azpilicueta
It used to be Terry who was Mr. Reliable for Chelsea; well, Azpilicueta has taken over that mantle now. He may not be Chelsea's best defender, but he is the most consistent. Conte knows he will get a performance from the Spaniard wherever he plays him, which shouldn't be underestimated.
He's been a big figure again this term, rarely putting a foot wrong and giving Chelsea a strong defensive base.
3. Eden Hazard
He's barely back from injury, but Hazard's performance in the 2-1 win in Madrid propels him right into our top three. It was a reminder of just how talented he is. Few players have tormented Diego Simeone's side in the way he has, and he was unstoppable.
Hazard as the false nine has to stop, but as a 10 in Chelsea's 3-5-2, he looks impeccable. Just as he does as the inside left in the 3-4-3. A few more performances like that one in Madrid and Hazard will inspire Chelsea to silverware.
2. N'Golo Kante
Last year's Player of the Year, Kante shouldn't be too far from the shortlist again this season. His performances have held up, proving what an asset he is to Conte's side. He provides a structure and shape in midfield that allows others to get forward and attack weak spots in an opponents defence.
His role has changed this season in the 3-5-2, though. It's Bakayoko who has been holding more, with Kante getting forward to support attackers. He's not as effective in the final third as he should be, although his goal against Leicester in September suggests he has the ability to change that.
1. Alvaro Morata
We were all concerned for Chelsea without Diego Costa leading the line this season. Well, Morata has shown that those fears were premature and needless. His six Premier League goals in seven appearances—including a hat-trick against Stoke City—have meant the transition from one striker to another has been seamless.
Time will tell if he can be as effective in front of goal as Costa, but what's key is that Morata's link-up play means Chelsea are able to play a different way. They have an ability to go long or play through defences now, which Morata is a big part of.
There's work to do with his understanding of team-mates, but if we take his partnership with Hazard against Atletico as a benchmark, the signs are all positive.