Giaccherini played for Sarri at Napoli.
“It's difficult to do that at Juve, above all because there's Ronaldo, who has his own way of playing. You cannot ask him to do certain things…
“Sarri struggled because this team was built over the years to play a very different type of football. In my view, Mandzukic would've been ideal, but the club made other choices."
He added: “Juve play at a much slower tempo, they don't do one or two-touch football, because there was a different quality of player at Napoli.
“The Bianconeri have players who can change a game, whereas at Napoli it was more of a team effort. Juve play for Ronaldo, so it's Sarri who has to adapt and not vice-versa."