Guzman and Miller have been about the same. All things being equal, I'd prefer the pitcher with the greater upside. Upside is great, actual performance is better. Guzman has been hurt just as much, if not more than Miller. Miller has done well enough to earn a spot. He's been healthy and made every start so far, that is a good sign. People forget how good of a pitcher he used to be. He'll most likely never see that type of success again, but he can still be usefull. Miller has missed more time than Kerry Wood. Unlike Guzman, Miller isn't likely to get better. There's no way of knowing if Miller will be healthy enough to withstand pitching an entire season; both he and Guzman appear healthy right now and that's all you can say... I've watched/listened to all of his starts this year and this is clearly his best. It's about time! This isn't the Miller of the early 2000's I'm waiting for the other shoe to drop. If Guzman pitches well out of the pen he will get his chance, I'm not worried about that. I would worry about him starting the season in the rotation. Guzman has had hot springs before. In his 10 starts last year he put up the following numbers: 10 GS 56 IP 68 H 46 ER 7.39 ERA Let him adjust to ML level in the pen. I also don't think Prior should be handed a spot just because his name is Mark Prior. He has not earned it, Miller has been better. Take those numbers with a grain of salt. You can make a similar argument against Rich Hill... The way things currently stand, I don't think there will be room for Guzman (unless Wood is DL'd). Are you opposed to the idea of giving Miller starts if he looks good enough to hopefully draw more interest when the Cubs trade him? Guzman isn't going anywhere, but Miller can net more if he goes out there and wins games.