The pair played together at Cagliari.
Srna said, “Nicolò is a great guy, a wonderful player and has a strong personality, which is very important in life. When we were sitting down to lunch together, I told him the time had come to leave Cagliari.
“He had climbed up a level and if he wanted to keep growing as a player and a person, he had to join a top club. Inter are helping to showcase his talent and in a couple of years Barella will become one of the best midfielders on the international stage.