Isco's problem with playing time is not really about how much he's gotten this season but the fact that he's always going to be on the bench if James Rodriguez is fit.
James got injured, and Isco played a lot - and really well. Then James returned on the 8 November, immediately played the Classico when he wasn't match fit and Isco hasn't started a league game since.
He's also capable of playing in central midfield, not just behind the striker, so he could take up a lot of game time for Yaya who obviously can't play 180 minutes a week.
Then you've got Silva, who's missing more and more games every season, and his ankle seems like it's just one bad challenge away from putting him out for 8 weeks.
And Aguero is always injured, so Sterling could play up front and Isco come in as Bony isn't impressing.
There would be loads of opportunities for him to play.