Ibrahimovic signed the midfielder last year from AZ Alkmaar and has seen the Dutchman take his game to another level in Serie A.
Ibrahimovic told UEFA's website: "I think he is the player who has grown the most in a short time, because in these two years we have brought in many players, with different profiles, different characters, but he has had an incredible growth. Not many fans or many people knew him, even though he had done great things at AZ. He is proving to be a high-level profile. And I think he can grow even more."
The Swede also said: "I believe in the project and I believe in what Milan represents. I believe I share the same vision as the people who work there and the same as the owners, because they also want to do extraordinary things. They aim to make history, to win, and when it comes to winning, that's when I feel I'm alive because I also want to win. I do everything to win and I don't give up until I succeed.
"I've played in many clubs - fantastic clubs, big clubs, big teams - but the club that has given me the most in my career is Milan. I've been here twice and I really like everything that Milan represents. The first time I played at Milan, they gave me a lot of happiness. The second time they gave me love, and now I'm the one who wants to give something back to them."