I would start him tonight. The start last week where he was brilliant was also against Pittsburgh, and even though they now have Giles back in the lineup, they still aren't an offensive threat. Also, I believe that on Saturday, he only really gave up one legit hit, and the second one that allowed one of the runs to score was the one that went off his leg into center field, which is just bad luck. Then, the player that relieved him allowed a double, letting the second run across.
Miller is 4-2 with a 1.85 ERA career against the Pirates. He is 1-2 with a 2.35 ERA career at PNC Park. Also, Brian Giles only has a .100 career batting average against Miller.