Sarri has guided Chelsea to Europa League glory and to third place in the Premier League during his first season in charge at Stamford Bridge, but looks set to return to his homeland with the Bianconeri.
The Italian tactician is reported to have flown to Turin on Saturday to hold talks with Old Lady officials, and a move could be announced in the next couple of days.
Juve will have to pay compensation and Chelsea could pass it straight on to Derby County as they look to lure Lampard away from the Championship club.
The Blues legend is the bookies' favourite to get the job, but his uncle, Harry Redknapp, believes it might be a mistake to take it so early into his managerial career.
"It's a difficult one for him," Redknapp told talkSPORT. "He's at a good club, Derby is a great club.
"He's had one year there and he's got a good relationship with the chairman, so it would be difficult to leave. But if the Chelsea job comes up, will he turn it down? It won't be easy for him."