Milan won 3-2 in New York on Saturday via goals from Lorenzo Colombo (twice) and Marco Nasti.
Fonseca later said, "We have good sensations. The most important thing is that we put into play what we worked on during the week. The players did what I asked of them: play with courage, keep the ball, find the spaces that are there.
"We have a lot to learn and I think the game we played today was positive. It was important to win to gain confidence."
On the style of play, Fonseca continued: "We are starting to see our intentions. We need to improve the timing in doing things and I am active on this: getting the players to arrive at the right times and in the right positions.
"The players are returning. We need to integrate them into our possession and continue learning: there is a lot to improve defensively and offensively."