Gregucci was brought in this summer as a specialist defensive coach and spoke to Radio CRC.
"I don't know if the club will lay siege to Napoli for Cavani, but every club with a player of the highest level will know they'll be courted by bigger clubs," said Gregucci.
"Mancini decides the transfer targets along with the new directors. If you ask the clubs who can afford Cavani, for example Real Madrid, Bayern Munich and Manchester United, then I think they'd want Cavani just as Manchester City want him.
"However, what the player wants is the predominant factor in negotiations and it seems to me that Cavani is happy at Napoli.
"If he should want to undertake a new adventure, then he will tell the club and I expect they'd let him go. Cavani is among the world's top five strikers and is doing great things. Napoli invested heavily in him, but the player's intentions are decisive."