sometimes relievers just end up dead overnight. doo isn't the first or last reliever to show some cracks, rebound, then just fall off completely. he's probably cooked, best case he's a middle of the pen guy.
Yeah, I've said it before and I'll say it again: relief pitchers are the placekickers of MLB. Sometimes they just fall apart out of nowhere. Both roles are highly psychological, so that's likely a factor.