It's a little strange that Mike Adams, who was sent down to make sure that he could get more regular work (according to Ned), was replaced by another pitcher, this time former-/semi-/maybe-prospect Ben Hendrickson. Thanks, guys, for bringing it up in this comments. Here's the MLB.com story.
In case you're new to Brewers fandom, or don't have a very long memory, here's the backstory on Hendrickson:
He's had a good start this year, though as battlekow points out his peripheral stats don't suggest he can maintain his low ERA, even at triple-A. The MLB.com article suggests (rightly, I suppose) that Ben will pitch middle relief, a role currently empty since Rick Helling is on the shelf and Jared Fernandez is in Nashville. (Speaking of whom, I'd imagine Jared will take Ben's spot in the AAA rotation.)
But...I'm really torn about this, and I'm probably thinking far too much about it, but if you've got seven relievers already, supporting a starting staff that can be expected to eat a fair number of innings, what's the use for middle relief? If you figure every reliever on your staff can pitch one inning every other day, and we've already got seven, we just need 5 or 6 innings out of our starters. That's not even the case, because several Brewers relievers can go multiple innings: really, only Turnbow and Kolb seem locked into one-inning stints.
Point being, if Adams needed to be in AAA to get his (one inning every few days) work in, what on earth are we going to do with Hendrickson? He's as much of a "prospect" as Adams at this point. I want to see him taste some success at the big league level, but we just have too many guys in that bullpen.