Hatch had been pitching better since a rough April. He had 44 Ks to 11 walks in May and June. They gave him a chance and he sucked ass so he won't be getting another one possibly ever again. They acquired Banda midday and needed to make room so Castillo was sent down to AAA presumably to start so he'll be the next one up if needed.
The team has a youthful core, a top offense and a very solid rotation. The weaknesses are rotation depth and the bullpen and I'm sure the team is itching to make some trades to address that it's just not quite time yet. Plus, you have to factor in where we are at. The team isn't catching the Yankees but is very likely to make the WC so there's no sense panicking and forcing trades early. Some deals will get done at the deadline you crybabies!