Too many here have the emotional maturity of 13 year olds.
Yaya is not playing because he does not fit Pep's system. Simple as that. He wasn't playing before agents comments. Pep getting into a pissing contest with his agent makes him look vindictive and serves no purpose. It doesn't look like his agent will apologize, then what? If Yaya is not going to play, then what purposes is he serving? Why not just release him with all the money due? If they keep him around while telling him he won't play then its PURELY VINDICTIVENESS! Before you could have made the argument that he would be cover for injury crisis or he could play in league cup games with the kids, but Pep has come out and said he will never play without apology (which is not coming).
Pep should have taken the high road and ignored his agents comments. Instead what will happen is Yaya will get his free release in the Jan period (with probably full payment), and what does the club get in return? Possible distraction, bad press, and horrible way to break ties with one of the more influential players of the club.