The former Napoli boss has high expectations of the young Croatia midfielder and says he remains close with Antonio Cassano following their spell together at Sampdoria
The 19-year-old impressed with some fine performances in the second half of the 2012-13 campaign after joining Inter from Dinamo Zagreb and Mazzarri is keen to work with the midfielder next season.
"I prefer not to say too much until I've actually coached the players. He's certainly promising though," he told reporters at a press conference.
"I don't know him personally yet, but I've played against him when coaching Napoli so I can see he's a promising player. He's talented but also young.
"I'll be able to say more once I've spent a month or so with him."
The former Napoli boss then went on to discuss his relationship with Antonio Cassano and says he remains close with the attacker following their time together at the Sampdoria.
"I have an excellent relationship with all the players I've coached. You saw what happened last year when we played against Inter and lost.
"There was a throw-in and Cassano came over to our dugout to say hello to me. I think that says it all."