I really hope Pete doesn't go the way of Chris Davis (I still love that big, hairy baby), but the one thing that jumped out to me amongst all his early bad numbers is his bat speed.
He's consistently been elite (at least 75MPH and 90th percentile and above for several years running). So far this year he's at 73.1, a 2.3 MPH drop from last year that moves him from elite to above-average (66th percentile). He's still strong enough to have elite exit velocities when he hits it, but if he bat is really starting to slow down...