In the last match of the day tomorrow, Milan will host Empoli. I think Milan boosted their morale by winning with a difference against Napoli. They hadn't won for 3 weeks but it was important for them to win 4-0 away against Napoli. Since they will play at home against Empoli, the advantage is definitely milan. But they can also rotate in this match as there is a champions league match during the week. They won't risk it because they will face Napoli.
With a fairly busy schedule for Milan, it is likely that they will not appear with the main squad when they host Empoli. Maybe they will save the energy of their main players to better prepare for the match against Napoli in the champions league. But statistically even H2H Milan is actually still ahead by winning the game against Empoli. So in my opinion this will be an easy match for Milan, at least they have to win by scoring 2 goals to secure their position in the standings.
As we said, they will rest some of their players and they don't want to risk injuries. As you said, they have a busy schedule and in a short time they will have 3 games with napoli. Because of this, they might not want to concentrate too much on this match. It will be a squad that we will see completely before the game starts. Maybe the coach will bring players out in the second half to rest them. Milan's point difference with their rivals is small and they need at worst a draw from this match. Otherwise their rivals are strong enough to close the gap.