Higuain joined Milan on a season-long loan from Juventus in July with an option to make the deal permanent, but he has struggled to settle at the seven-time European champion, scoring eight goals in all competitions.
Higuain had his most successful season under Sarri, breaking the Serie A goalscoring record with 36 goals in the 2015/16 campaign.
In total, the 31-year-old found the back of the net 71 times in 94 appearances during his three year reign at the club after which he moved to the Allianz Stadium in a mega deal around £75m move to Juventus in 2016.
"Higuain must find the real himself, he is living in a different situation for him, he left Juventus and he is here on loan".
Chelsea are closing-in on a £36m deal to sign Gonzalo Higuain after the striker agreed to join the Blues on a contract worth around £140,000-a-week, according to reports in Spain via the Mirror. There's no point following rumours and gossip. "Seeing as he is here, he needs to get down and actually do something for this team".
Today is Sarri's birthday, so if, as the report says, he has met Nicolas Higuain in London today, it says a lot about both his work-ethic and how desperate he is for a striker.