Arda Guler has been expected to be in Real Madrid squad for the Mallorca game so far and I hope this doesn't change again. This is a game he can finally have a chance in for the first time. Ancelotti would keep him on the bench until securing the win by a decent score. After that maybe for 10 minutes or less we might see him on the pitch.
I don't think he has had his time with injuries completely. Real Madrid must have been working on his physique to be better on one hand. He has a good talent but as long as we don't see him on the pitch it doesn't matter unfortunately.

Its hard for manager actually to trust a young player when the table is getting very competitive which is what is happening right now. After Madrid are ahead with considerable gap on the table and things doesn't matters much, then manager might give him chances much more frequently. Right now Guler is out with injury and manager might wants to make things smoothly for Guler to settle up after a long term injury. There is no rush, Ancelotti has plenty of options and Guler is a massive talent so manager just wants to make sure that everything goes on smoothly.