It would only take one big hit/game to change the narrative. Look at Rhys (I mean, he got booed at the home game introductions - seriously! - and could stand to step up again as well, but despite his defense and overall numbers he has delivered a bunch of times. (Nick has quietly gotten hits and driven in runs but not enough, and still no power).
Castellanos actuallly is injured, don't forget. He wasn't the whole season but there's no chance he's actually recovered from the oblique injury. His season probably ends in September on a non-playoff team. Doesn't seem to hurt him when he runs but mechanics and timing at the plate + pain (or fear or reinjury) could be a factor.