The Fulham manager won promotion through the play-offs with Chelsea's west London rivals and he is now in talks to take over at the club he used to play for.
Sarri left Napoli at the end of the 2017-18 season but is still tied contractually to the Serie A runners-up.
Napoli's president Aurelio De Laurentiis has subsequently proved too difficult to negotiate with for Chelsea, despite Sarri being keen on coming to west London and the chief affirming he would be "reasonable" in any talks .
Chelsea have yet to make the breakthrough with any manager but Jokanovic is one of the leading candidates, with Laurent Blanc having also entered preliminary talks.
Luis Enrique isn't yet interested in a return to management despite being contacted over the soon-to-be-vacant hotseat.
Antonio Conte is still set to depart Stamford Bridge after finishing fifth in the Premier League.
His exit has yet to be formally announced, but he will be due compensation - worth around £9 million - to cancel the year left on his contract.
However, if Conte accepts another management job in that time he will no longer be entitled to compensation.