To be honest, if AA fills out LF, 2B, and the pen adequately, I don't think we need a SP upgrade. This lineup as is will rake, imagin if Melky or something similar is put in LF, we won't have any issue scoring runs. Legitimize the pen with a few solid but unspectacular arms and I think we are in great shape. Maybe bring in a short term option for 2B and see what Travis can do later in the season.
We already have Cecil, Loup, Sanchez, and Estrada in the pen, all of who were good as relievers last season. Delabar could be a bounce back candidate as well. Two more RP with track records and I'm really comfortable with this team moving forward.
Seriously what other lineup can rival Donaldson/Bautista/Edwin?