With someone like Rich Hill, the control was there in the minors but not in the majors. Marmol has never had better than average control, and generally it's been rather poor. At this point, if they see him as a closer prospect, I don't think they'd be hurting his development by shifting him to the bullpen. The Cubs have a lot of guys in the pipeline who are really starter-only prospects (Gallagher, Veal, Samardzija) and if Z is signed, there are four guys set in the rotation for the next couple of years. Meanwhile, the pen has a good number of veterans (Howry, Eyre) and guys who are marginal (Ohman, Cotts). So I favor moving him to the bullpen. There's nothing wrong with stretching him out and letting him work on his pitches from the rotation now even if he is a closer prospect. We once viewed Aardsma as a closer prospect, and he did some starting as well just to help him work on his pitches and command.