"We will have a better team than Milan this season, for sure," he said. "Why? Because Milan have lost its two best players."
Ibrahimovic has signed a three-year deal with Carlo Ancelotti's side and took just three minutes to open his account in a friendly against DC United.
The Swede said: "On my goal, I moved to find the right space and I hit the left.
"I'm still in preparation, I'm not 100 per cent but I work to find an optimal shape. Playing those games will help me get there."
Ancelotti was satisfied with his side's display, believing it did enough to emerge victorious.
"We played well and deserved to win," he said.
"The weather conditions made it something of a strange game. We were also up against a side who were in perfect physical condition. We did a lot of running and that's a very good thing in terms of our preparation for the new season.
"July has been a very good month for the team and I think the next 10 days will be too! We will be ready for the start of the championship. Zlatan made a fantastic start to the match with a very good goal too."