If you assume Alexandre Lacazette will be a second string player, then what about Endrick fate?
I think the news will not really come true because right now what Madrid needs is a defender who has quality talent and can be used as a second string player in defense.
On the one hand, Madrid front line is already very perfect because it has Endrick, Mbappe, Bellingham and Arda who can be rotated by Ancelotti. I really hope Ancelotti will not do this and focus more on defense first.
I would guess that, not that I think they will get Lacazette, if they do this, then they are just doing it for a six month stint there for a season because they didn't like what they saw from Endrick yet. This is normal, I mean look at Arda they have, he is a midfield and plays a bit on the right side as well, and they have plenty of players there too, not like they do not have enough, and yet they got him anyways, so young players could be third string and that would be fine for everyone. Lacazette and Endrick both could get minutes considering how many games Real Madrid plays, having a bench to your bench is a great deal if you can afford it.
Players would be upset about not getting enough minutes that's for sure, but they would always have fresh legs whenever they want to. Mbappe could have injury, booking, fatigue and all that, so then they would just play these two, and that would be great for them. You can start with Endrick, and sub in Lacazette in 70th minute since he is older and could provide less minutes.