With all the pitching injuries this year (a front we've been pretty lucky on), if Miley put together 3 good starts, some team might blow us away with an offer at the deadline. We have two guys that could slot in easily into #5 slot in rotation in Antone and Mahle.
Keeping all three (if they are pitching well) is a real nice luxury. So I wouldn't trade him unless the offer is sweet, but it would nice to have the option.