If Arda Guler fails to break into the Real Madrid first team then it will be difficult for him to get a place even though Turkish fans are not happy with the situation.
Arda Guler is still quite young and may need to be patient to get regular playing time in the first team because there are now many great players in the same position in the Real Madrid squad.
Ancelloti has played Arda Guler and rotation has been done so that some young players can show their best skills and I think it will only take time for Arda Guler to become an important player for Real Madrid in the future and if he can be patient then there will be a time when Arda Guler will be a key player for Real Madrid.
You need to understand that Carlos Angelotti didn't trust young players. He always prefers experienced players.

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https://www.turkiyetoday.com/sports/ancelottis-one-sentence-on-arda-guler-good-and-ready-to-play-123657/First of all Arda is showing good performance. It's not like he is not showing good enough performance for which he does not deserve the first team.
So, if you ask me, a big reason why he is not getting as much playing time as he wants is because Real Madrid is trying to keep him safe from injuries. You know, he has already faced some injury problems with Real Madrid.
So maybe Real Madrid is just not risking him getting injured at such an early stage. However I think it is time for him to get 90 minutes. Maybe not consistently. But I think, give him 90 minutes for 2/3 matches. And then give him some rest. That is if injuries are the biggest issue with him. If injuries are not the concern, then I do not see why he cannot get 90 minutes.