The 59-year-old Italian replaced Antonio Conte, who was sacked on Friday after two years in charge in which he won the Premier League and FA Cup but failed to gain the power he wanted at Stamford Bridge.
Here, take a look at a few pictures as the two new arrivals look marvelled at the infrastructure at Cobham, Chelsea's training complex. Indeed, in Europe's big five leagues last season, no player had more touches of the ball per minute than Jorginho.
City are also said to be furious at the handling of the situation by the player's agent Joao Santos and Napoli president Aurelio De Laurentiis.
At the time, Sarri said: "I was just irritable".
The Senegalese centre-back won't keep cheap though if the latest reports are to be believed with Napoli desperate not to lose any more of their best players to their old Manager.More news: Industrial park blast kills 19, hurts 12 in southwest China
Telegraph Sport understands both incidents came up in negotiations between Sarri and Chelsea, and the 59 year-old was left in no doubt that any similar comments would be deemed completely unacceptable.
"I am excited to play in such an intense league, for a team that gives everything to play and win", he told the club's official website.
Chelsea hailed Sarri's "scintillating brand of expansive, attacking football" in their announcement, sentiments echoed by club director Marina Granovskaia.
"It is an exciting new period in my career", said Sarri.
And having led a title charge with Napoli last term that only fell away during the final few games of the season, he is well poised to improve results at Stamford Bridge.