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.