He needs to actually talk with him. Was Gio a prick in the WC? Sounds like he was. Was Berhalter right to not play him? Sounds like it.
However, the drama all kicked off because Berhalter started blabbing about stuff to the media after the WC and now he is doing it again. It is understandable that he would not make contact prior to the official announcement, but to still not have reached out, and then to comment on the player, is just stupid. You are the coach, reach out to him and extend an olive branch, if for no other reason than you can say to the media: "We spoke and had a productive conversation, and I am looking forward to working with him." Instead, the continuing narrative is going to be "Will Berhalter play Reyna?" for the foreseeable future. One simple phone call, even to say "Congrats on the cup, you played fantastically" would have prevented that.