Cisse's strike ended Milan's Serie A goal drought against Juventus stretching back to May 2023, while making him the youngest player to score in his first two away games during the three-points-per-win era.
Highlighting fundamental weaknesses in possession, Amorim added: "We have individual quality, but the simple things are the most important things, the way we receive and pass the ball, the fundamentals of football, today we were not good.
"My feeling is when my team doesn't have the ball, we struggle. When Juve put a lot of strikers in front, we defended well, but we suffered more when we lost the ball and they had transitions.
"We are not going to change the way we play, because we know that in some games it'll go well, in others it won't, but the important thing is that we fight to win. We could've won today, but again Juventus didn't deserve to lose either."