With Antonio Conte still expected to leave Stamford Bridge this summer, the Blues have struggled to find a replacement due to the complexities of hiring primary target Sarri.
Napoli president Aurelio De Laurentiis - who has already hired Carlo Ancelotti to replace Sarri in Naples - remains firm in his stance that Sarri's £7 million ($9.4m) release clause be paid as compensation despite it officially having expired on May 31.
Chelsea's reluctance to pay such a fee has led them to look elsewhere, with former Paris Saint-Germain boss Laurent Blanc and Fulham manager Slavisa Jokanovic high on their shortlist.
Blanc has already begun sounding out potential backroom staff should he be offered the role, but both ex-Barcelona manager Luis Enrique and Roma's Eusebio Di Francesco have been ruled out of the running despite having spoken to Chelsea regarding the potential vacancy.
The five-time Premier League winners remain hopeful, however, that Sarri can be prised from his contract having led Napoli to second place in Serie A last season.
The delay in finding a new manager means the west London outfit have fallen well behind their rivals when it comes to securing new signings for next season.
Sarri himself has already highlighted Napoli defenders Kalidou Koulibaly and Elseid Hysaj as individuals he would want to bring with him to England, though Chelsea would still get final say on potential incomings as they have previously with other head coaches.
The confusion over the club's future is also creating uncertainty within the squad as star players potentially weigh up exits from the club.
Widespread reports have claimed goalkeeper Thibaut Courtois will look to move on this summer while Eden Hazard has spoken publicly on a number of occasions that he will only make a firm decision on his future once he knows who will be in the dugout next term.
The hold-up in appointing a manager also means that deals for Chelsea's annual army of loanees cannot be signed off on, with the Blues having had 35 players out on temporary deals last season alone.
And with owner Roman Abramovich having had to take up Israeli citizenship after being denied a Visa to enter the UK and with plans to extend Stamford Bridge on hold, there is a real sense of uncertainty around one of England's most successful clubs of the past decade.