The 25-year-old joined the Nerazzurri on the last day of the January transfer window from Stuttgart.
"Only time will tell how good Kuzmanovic can become," he told Sky Sport Italia. "But he has been great for us in recent games.
"His passing is superb.
"The win against Chievo was a good way to hit back against some of the criticism we have been getting.
"It was a difficult game for us, but it could prove to be a defining moment in the season."