It will be Real Madrid's first serious match since Mbappé arrived. Everyone is curious about how Mbappé will play in this match. Like you, I am curious about Ancelotti's formation. Because the talent they have is very good. There are more than one player in each position with high quality. For example, will young players Brahim Diaz and Arda Güler play? I think they will not be on the field at the beginning, but I wonder if they will enter the game later and in what role Ancelotti will evaluate them.
All eyes will be on Mbappe in tomorrow's match because it is his first debut with the Los Blancos squad. If I pay attention, of course Mbappe plays an important role as Real Madrid's goal machine in this match, in fact I am sure he will score a goal in tomorrow's match.
For Arda Guler there is a big possibility that he will come on as a substitute, but I would like to see him in the starting minutes.
Looking at the opponents you are facing, of course it is not an easy matter to beat Atalanta because they have quite a strong defense. But if you look at the comparison in the front area or the front line, of course there is no chance for the Atalanta defenders to relax.
My prediction is that maybe a big score will decorate this match.