It was an improved performance from Chelsea against Manchester City, but it wasn't enough for the Blues to earn a point against the current Premier League champions. Riyad Mahrez's tap-in from Jack Grealish's cross was enough to separate the teams despite a late push from the Blues to find an equaliser.
Graham Potter's side had the better of the opening period before half-time saw Pep Guardiola replace Joao Cancelo and Kyle Walker with Manuel Akanji and Rico Lewis. Those changes helped the Citizens establish themselves and exert plenty of pressure on the team, which ultimately paid off.
While there will be a degree of frustration, it was outing that felt a step in the right direction that was very much not present against Nottingham Forest. football.london takes a look at what we learned across the course of the 90 minutes.
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Hakim Ziyech in midfield and Conor Gallagher's challenge
With Mason Mount injured and out of the squad to take on Manchester City, responsibility fell to Hakim Ziyech to take on the England international's role. The Morocco international returned from having a very positive World Cup, and showing some creativity against Forest, to a role based in the centre of the pitch.
The former Ajax winger was disciplined in his defensive performance and made a midfield three alongside Denis Zakaria and Mateo Kovacic, before straying wider to attack when Chelsea were in possession of the ball. He showed good work-rate in the middle but only flickers in attack, but Potter was sure to highlight his ability on the ball as a key reason for his introduction.
He said ahead of the game: "Hakim gives us that quality in the final third. He's able to take the ball, he attacks the spaces and he's coming in off the back of a fantastic World Cup. He's itching to play and I think he's at a stage where he can help the team."
Potter's 4-3-3 formation may be considered more suitable for Conor Gallagher than systems that are based off of three central defenders but still did not come across his opportunity in the absence of Mount. His late cameo brought plenty of intensity to help turnaround the pressure Chelsea were under, but it appears it may be difficult for the young midfielder to earn his place in the starting lineup.
Graham Potter likes Kalidou Koulibaly
After Chelsea's draw with Nottingham Forest, few would have been surprised to see a defensive change. Kalidou Koulibaly struggled in his efforts against Taiwo Awoniyi to maintain his flat form since arriving at Chelsea in the summer.
Trevoh Chalobah, perhaps Chelsea's most consistent player under Potter, has not started since the break, despite being in training throughout the World Cup. Manchester City did not provide the young star with an opportunity to change that as Thiago Silva joined Koulibaly in the defensive pairing for the third game in a row.
Instead, Potter opted to make use of Koulibaly on the left side of his defensive pairing, a move which may have been more familiar for the defender who has predominantly been used on the left of a back three at Stamford Bridge. It was a move that seemed to pay off, though Koulibaly was not perfect, with Chelsea's defence seeming much more secure for large stretches. Whether it is enough moving forwards remains to be seen, but the duo definitely appear to be Potter's favoured pairing.
Chelsea can't avoid injuries
When discussing Mount's injury ahead of the game, Potter said: "It never rains, but it pours".
Little did he know that he would be without two more players just 20 minutes into the match against Manchester City. Raheem Sterling appeared to suffer a hamstring issue after a collision with Stones, while Christian Pulisic saw his chance blocked by John Stones and needed replacing himself.
The duo see Chelsea's injury list hit 10 players, a group who could make a good team of their own: Edouard Mendy, Reece James, Wesley Fofana, Ben Chilwell, N'Golo Kante, Ruben Loftus-Cheek, Mount, Pulisic, Sterling and Armando Broja. The number of muscle injuries are sure to be a cause for concern for the Blues and something they will look to overcome quickly.
Chelsea will give youth a chance
While Chelsea have struggled for form and suffered injuries in Potter's latter games in charge of the Blues, not providing opportunities for youth has proved frustrating for many. Potter had a free-hit of sort against Dinamo Zagreb in November but started a strong team despite seeing the likes of Dion Rankine and Lewis Hall in first team training in the build up to the game.
The latter received his chance in the Carabao Cup against City and maintained his place against Newcastle, but had not made it onto the pitch against Bournemouth or Nottingham Forest. Omari Hutchinson has been a regular in Chelsea squads since the Blues' trip to Brighton in October but never been afforded an opportunity.
That changed on Thursday night. Injuries may have facilitated the opportunity but Carney Chukwuemeka entering the fray early, provided the former Aston Villa youngster by far his longest stint in Chelsea colours. Then, with the game still in contention and 20 minutes remaining, Potter decided to make a triple substitution. Hall and Hutchinson entered the pitch alongside Conor Gallagher with each of the trio making an impact.
The Chelsea coach opted to utilise the youngsters, and although there were few forward options on the bench, he chose to sacrifice the likes of Pierre-Emerick Aubameyang, who had entered the pitch late himself. Potter was clearly impressed with what the substitutes provided, and his reference to their personality can only be a positive stop for them ahead of the FA Cup.
Potter said: "We had to freshen it up but Lewis and Omari are young players starting out and Conor gave everything. It was nice to have that personality from the bench."
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