Chelsea's win streak has come to an end, with the Stamford Bridge side drawing 0-0 with West Ham at the London Stadium on Sunday afternoon.
Here are four things learned from watching the goalless encounter.
4. N'Golo Kante Isn't Suited to Wing Play
N'Golo Kante's being played out of position was most apparent on Sunday. Maurizio Sarri's decision to field the Frenchman on the right flank was seemingly vindicated by the team's overall performances in prior games, but Sunday's London derby saw the coach get exposed.
Admittedly, it will be difficult to figure out how to use Kante and Jorginho together in a 4-3-3 and have both players play to their strengths. However, Sarri should be able to come up with a better plan or simply force the player to improve in the current system.
3. Chelsea Should Get a New Striker in January
Chelsea just aren't getting enough from their strikers despite their overall attacking brilliance. Olivier Giroud and Alvaro Morata have combined for just one goal so far this season and the latter is going through a very unlucky spell.
A case was made for the Spaniard to be handed a chance at redemption under Sarri this term, but he's proven to be mostly ineffective to this point. And, while Giroud has been good linking up with Chelsea's other attackers and providing assists, he's better suited to coming off the bench and can't be the Blues starting striker all season.
2. West Ham Aren't Planning to Sit Back
West Ham would have been forgiven for sticking to a purely defensive plan, albeit playing at home. Yet they nearly shocked Chelsea on a few occasions and should have probably nicked the win as they did have the better of the chances.
Manuel Pellegrini's tactics for the match were well thought out and, to be fair, was only undone by misfiring attackers. The manager has likely taken several positives from this latest result as he looks to keep improving his squad.
1. Sarri Should Have Rested More Starters in Midweek
It was shocking to see how many regulars Sarri kept in the starting 11 when Chelsea played PAOK in the Europa League on Thursday.
It was expected that the likes of Ethan Ampadu and Callum Hudson Odoi would be in the starting lineup but the manager played a very strong side and their delayed flight wasn't of much help either.
The Blues looked leggy and out of sync on occasion, during Sunday's draw, and it was clear that their midweek exploits had taken a toll. While Sarri's desire to win the Europa League is understandable, considering he's never won a trophy as a manager, save individual accolades, he should use such opportunities to give his younger players game time, as well as rest his regular starters.