I did a lot of digging into PCA last night when discussing him with someone else off this board. I came to some weird conclusions at first, and then with more information, I've at least come to a thought process of what's happening. He's having a weird year offensively:
1. His in-zone whiff% is down 5% (good!) and his contact% is up 4% (good!)
2. His chase rate is comically bad: 45%+. It's over 53% (double last year) in hitters' counts.
3. Pitchers are using this to their advantage. He's seen an increase of 6% of non-competitive strikes. This doesn't seem like an accident. You've got a guy who will essentially offer at anything right now, especially when he's ahead.
4. His swing% in general is way up.
5. Pitchers are more consistently attacking up and out on him and he's not responding well to that pitch
I'm hoping a little break from Triple-A and a few days as a defensive replacement will calm him down a bit. The numbers look like a hitter who's struggling mentally right now and is way deep inside of his head. I can't say I know PCA the person, but my educated guess on looking at the data and the way he plays is that he's an emotional kind of guy and perhaps he's let his emotions get the better of him. He appears to be pressing, especially when he gets ahead in the count...he's trying to do too much. Perhaps he's desperately trying to force his way to Chicago, or prove that he's ready. Maybe he's struggling and letting that compound. Either way, the data makes me think this is a mental thing for him.