Il Diavolo were on top of the table after the first half of the 2020/21 campaign concluded but they finished the season in second place and 12 points behind city rivals Inter.
“The Scudetto is our objective, it is what we want,” Diaz said to La Gazzetta dello Sport.
“We were close to doing it last year, and now we want to do better and finish first.
“Last year’s experience at the top will be very useful to us. It won’t be easy, there are great opponents, but we are a strong team.”
The 22-year-old made 27 appearances in his first Serie A season, scoring four goals and supplying another four assists.