Borriello, who has been playing in Spain for UD Ibiza, says Sarri joined Juve to fulfill his career ambitions.
He told TMW: "I am the last one who can speak given the number of teams that I have played for.
"People often talk about betrayals, instead it is only ambition. Sarri's cycle at Napoli was closed. And let's be honest: who would refuse the call from Juventus? It is still the strongest and (Cristiano) Ronaldo is hungry when he sees a trophy at hand.
"Given the historical moment, it will still be different from the past both for those who win and for those who lose.
"Who would I bring to Ibiza? (Miralem) Pjanic and (Dries) Mertens, both in love with the island."