You might have to go back to the basics, which include taking him out and making sure he does his business and if he doesn't, he goes back in the crate for a little while and then back out again continuously until he does number 2. That might reinforce that there's no play time until you go to the potty. Especially since in the AM you know that he needs to poop and pee. I've read a lot on here that sometimes these yorkies slip up and just need a quick refresher course. Maybe someone else can provide some other advice!
