In the 26-year history of the Premier League, it's difficult to remember many more dramatic shifts in style between Chelsea pre-Maurizio Sarri and Chelsea under the Italian manager.
Even Arsenal's transition from George Graham's defensive-minded football to Arsene Wenger's artistic attacking was aided by the one-season reign of Bruce Rioch, who had the demeanour of Graham but preached the importance of playing out from the back and loaded his side with creative talent. Chelsea have not had that type of transition manager and Sarri will have to initiate, and complete, a similar reversal himself.
It's not merely that Chelsea were focused on defending deep and counter-attacking under his predecessor Antonio Conte, it's that the club have largely stuck to that template throughout the 15 years of Roman Abramovich's ownership.