Liverpool are now the only remaining Premier League team with a 100 per cent record after Chelsea limped to a disappointing 0-0 draw with West Ham at the London Stadium on Sunday afternoon.
The Blues have been used to seeing Alvaro Morata and Olivier Giroud squander chances this term, but Eden Hazard and Willian were uncharacteristically profligate against Manuel Pellegrini's side.
The absence of Pedro certainly didn’t help. The Spaniard has been a revelation this season, but an injury against PAOK in the Europa League on Thursday meant he missed out against West Ham.
Maurizio Sarri will have been frustrated after watching his side rack up 71 per cent possession – which included Jorginho setting a new record for attempted passes in a game - without any end product. Indeed, it was arguably their rivals who created the better chances, Michail Antonio and Andriy Yarmolenko missing sitters of their own.
To make matters worse, key defender Antonio Rudiger limped off with an injury in the second half – to be replaced by Gary Cahill. Liverpool will be licking their lips at the prospect of the German missing the cup and league double-header against them on Wednesday and Saturday, respectively.
Rudiger’s pace is vital in an otherwise slow backline, and his potential absence could be crucial against a Reds attack which utilises the pace of their forwards frighteningly.
Certainly, Mohamed Salah, Sadio Mane and Roberto Firmino will fancy their chances of extending their perfect league record at Stamford Bridge next weekend.
Sarri has been cautious in calling his side title contenders - despite winning his opening five league games at the club - as he believes it will take time to implement his brand of football.
Stylistically, there has been a big change under Sarri given the more defensive style utilised by Antonio Conte and, before him, Jose Mourinho.
Until this week, Sarri had generally picked as close to his strongest starting XI as possible for every match. He will now be potentially forced to use more of his fringe players following the injuries to Pedro and now Rudiger.
The extra fixtures due to European commitments will provide an additional challenge for Sarri, who has complained about the fixture scheduling in English football.
"In Italy, if I play in Greece on Thursday I can ask to play [the next league game] on Monday night," Sarri said after the 1-0 win against PAOK. "But here I have to play again in 63 hours. It is not a big problem now because we have played only six matches but in the future it may be a problem."
This is a schedule he will have to get used to - with five more mid-week Europa League group fixtures to come before Christmas, and the Carabao Cup about to begin.
The next week is set to be huge for Chelsea. Following Sunday’s draw with West Ham, Sarri faces his first massive test as manager against a Liverpool side looking unstoppable right now.