Obviously, the most important and most compelling aspect of the spring is how the starting rotation will take place. This is the case not only because of the importance of having a deep rotation, but also because there are few locks to be a part of this unit.
Southpaw Clayton Richard figures to be the Opening Day starter, and it seems probable that Luis Perdomo and Christian Friedrich will also find themselves in this group. Beyond these three though, the race is truly wide open.
The Padres signed Jhoulys Chacin and Trevor Cahill presumably with the intention they would start, but this doesn’t mean they won’t have to earn it. If they don’t, Jarred Cosart, Paul Clemens, and even another offseason acquisition
Non-roster invites such as Kyle McGrath could also shape this competition if a serious impression is made. In other words, we have no idea how this rotation will look. We do know, however, that every outing of the spring will be heavily scrutinized and will help shape the rotation.