#1 Lack of motivation from the forwards
The key to Sarri-ball is how closely Hazard, Pedro and a striker play with each other, followed by the midfielders, who occupy wider areas in the middle third of the pitch. This brand of football concerns a lot of detailing, which was clearly missing from the away side.
Hazard and Gonzalo Higuain did not exchange many passes, Pedro tried to wriggle through the opposition back line single-handedly, and apart from a few surging runs from Hazard, there was no ingredient that Sarri wishes to infuse in his philosophy, with respect to his forward players.
In the first half, Higuain played a brilliant back heel to Pedro, who should have reduced the deficit to just one goal. Instead, the Spanish winger hit it straight at Ederson. He had another chance, and once again, Pedro failed to ask a bigger question to the City custodian.
Hazard made a few remarkable runs and got the attack flowing, Higuain found himself in spaces on a couple of occasions, but those were all in the first half. In the second half, due to the burden of the score line, the Chelsea forwards chose not to respond. They lost the sense of urgency and determination in their game.
As a consequence, we saw just one shot on target in the second 45. While you cannot overly whip the blame on them, the front three should at least have given something to the away fans to cheer for and made City back pedal to an extent.