Milan conclude their Champions League group campaign needing three points to finish in the top eight.
Pulisic said in his media preview: "Tomorrow we have a great opportunity: by winning we can get into the top eight. The Champions League is the most beautiful competition there is, we have to give everything to win.
"It will not be an easy game. I have already played here with Chelsea and I know how tough it is. There will be a fantastic atmosphere."
On coach Sergio Conceição, he continued: "The coach has given us more intensity and changed the spirit of the group. This is fundamental for us, considering that we play every three days and we don't have much time to train. You need a strong mentality."
Asked about Sunday's row between the coach and Davide Calabria, Pulisic said: "They solved everything right away. We have to look ahead and think exclusively about tomorrow's match. The team's spirit is high, especially after the victory against Parma."
And on new arrival Kyle Walker, he added: "He's settled in really well. He's a top-notch player and he'll be a big help to us."