Chiellini made the revelation in his new book, 'Io, Giorgio'.
The defender wrote: “I was close to leaving Juventus on two occasions, in 2010 and 2011. I happened to think about it.
“My agent had talked to a Real representative, but Mourinho had just arrived and demanded the purchase of his compatriot, Ricardo Carvalho.
“Juventus were happy to keep me. Marotta had just arrived. On the second occasion I met a City executive in Milan, but nothing came of it."