Tiredness and injuries being overplayed by his fans to save face in my opinion.
Making arguments is easy when you dismiss evidence with a wave of the hand. Two of the players that played against Chelsea hadn't played in weeks and did not play a single minute of football again. They were clearly not over their injuries. You can ignore that if you want, there's no law that says you're not allowed to live in the Phil Osophy Mind Palace. The rest of us live here in the real world.
Then you have ... the japanese kid on loan too .... such an amazing development by the young bunch.
The reason why the "japanese kid" is on loan is because he's japanese. Real Madrid already have three players who are not EU in the squad. They're all "young." They all got a lot of minutes this season.
Because we're not in a rebuild. This team should be ready to start winning something.
It's also just not really true that Zidane does not like youth players. He takes a conservative approach, but young players play.
The misleading perception is created because the number of young players around Real Madrid in the last seasons is ridiculous. You have Llorente, Hernandez, Vallejo, Hakimi, Ceballos, Odriozola, Brahim Diaz, Vinicius Jr., Rodrygo, Odegaard, Militao, Reguilón, Mayoral, Valverde, and Jovic. That's
fifteen players. And these are the players that have actually played for Real Madrid. There are others, like Kubo and Reinier, and promoted players, who are just on loan. It all adds up to an entire squad.
Needless to say, you should not replace your entire squad with young players over a four-year period. You should especially not do something like that if you don't have to. Real Madrid didn't have to. The squad isn't as old as people seem to think. A lot of the "veterans" are not even 30 years old (Varane, Carvajal, Casemiro, Isco, Vazquez) and some of them had not turned 30 when Zidane came back (Kroos, Nacho).
The whole thing with RM needing to be "rebuilt" came from the fact that the players were
playing badly. All of them. Young, old, you name it. The typical, hysterical fan reaction to this is "we need an entire new squad" because "they're all washed up." Zidane came in, did
management, and got most of the players to play well instead. Not all of them, but most of them. Some of them were washed up, as it turned out. But most of them weren't.
RM currently have four young players that get a lot of minutes: Vinicius, Rodrygo, Valverde, and Militao. That's not a bad amount. Ideally Jovic would have taken over Benzema, but he is a bad transfer and sucks. Ideally Odegaard wouldn't be a weak-as-piss baby, but he is.