It could very easily be a case of a guy playing his first full season at the MLB level as a shortstop and having fatigue starting to set in. He's not striking out a lot. Indeed, his K rate is better than it was last year. His BABIP is .250, which is very low. That suggests some bad luck at play as well. I'd be more concerned if he looked overmatched at the plate. That clearly isn't the case. My biggest concern is that he hasn't seperated his offensive struggles from his defense. He's been kinda shaky the last week or so.