It takes time for all of that to form, it is not easy for a coach to form a solid team, the players in the AC Milan squad are good enough, it's just a matter of time, a 1-0 defeat is not a problem in my opinion if in the second leg AC Milan is able to turn the advantage of the match around, because this is their moment to survive in the next round, even though Jaoa Felix has performed well but not optimally, that's why it takes adaptation from all players who need him to play more to find out the game that Sérgio Conceição wants.
There was bad luck that they had to feel in this match so that they could not get a satisfactory result. If you look at the way they played, they should have gotten a draw. However, that is the reality, we cannot predict what will happen to a team even though they performed better than the opponent they faced. There is still a chance for them in the second leg later, being 1 goal behind is not a far distance, they can reply when playing in front of their own supporters. With the note that they must be able to play well.
Of course it takes time for Conceicao to be able to make Milan even better and of course at this time Milan's defeat at the hands of Feyenoord is a worrying thing for AC Milan fans and of course in my opinion Milan should have been better in the second leg because Conceicao definitely already knows Milan's shortcomings and of course we'll see what Conceicao will do to make Milan players even better. In my opinion, Milan's weakness in terms of utilizing opportunities is still not bad because of course there were so many opportunities created in that match.
It is true that the second leg is waiting for them and what is certain is that Milan must be able to make good use of this because of course if they lose again in the second leg, then Milan's hopes of advancing to the top 16 will be gone and what is certain is that in the next match of course Conceicao will try as much as possible to keep Feyenoord's defense open and Milan must also be alert to Feyenoord's attacks which are always sharp. but honestly I see that Milan, by competing at home, will definitely be able to win and Conceicao will definitely be able to make a better strategy and will learn from their mistakes when competing at De Kuip. However, if Milan loses at Sansiro, Milan will of course have to admit that they lost to Feyenoord and have to admit that Feyenoord is better.