Aaron Harang has pretty much owned Milwaukee over the last 2 seasons to the tune of a 2.50 ERA over his last 5 starts facing them. Unfortunately, at the Reds have been known to do with Harang, he only has a 1-0 record in those 5 starts. The current Brewers roster has hit Harang fairly well (10 HR in 247 AB), but Harang has managed to hold them to just a .311 OBP, which has helped keep their run production down.
Dave Bush has handled the Reds pretty well the last two times he's faced them, giving up just 10 hits and 3 runs in his last 15 innings against the Reds. Willy Taveras and Brandon Phillips are the only 2 hitters to have faced Bush more than 10 times, and neither have hit all that well off of him.
Hopefully the loss of Joey Votto, who is clearly the heart and soul of this team, does not affect their mental state too much. This road trip is too important for them to not be on their game.