With pitching it is worth distinguishing between what you start the year with and what you finish the year with. Last year EOF, Venters, Hudson and Gearrin fell by the wayside. Maholm and Beachy too. In 2012, Jurrjens, Beachy and Hanson were in the rotation at the start of the year but were no longer there at the end. In 2011, Lowe and Jurrjens declined sharply in the second half and Moylan was lost to injury.
With that in mind, here are the pitchers who I think will be there at the start of the season and some spare parts who are likely to feature prominently.
Starters: Medlen, Minor, Beachy, Teheran, Wood are the incumbents. The pecking order in terms of depth looks like this: Floyd (once he is ready), Hale, Maya, Martin, Thomas, Northcraft. I expect Graham to start the season in AA and to stay there until his shoulder is shown to be sound.
The pecking order will undoubtedly get scrambled based on performance and injury. But our depth is really quite good. I'll repeat something I've said before: while there no ace currently in our rotation, all five are fairly close to ace caliber and could reach that status with relatively small improvements in their strikeout and/or walk rates.
Right-handed relief: Kimbrel, Walden, Carpenter, Gearrin and Varvaro at the start. My take on the pecking order among the spare parts looks like this: Vasquez, Hale, Martin, Obispo, Schlosser, Northcraft, Graham, Simmons, Harper, Jaime, Hoyt, Lamm.
We have tremendous right-handed pitching depth. I list Gearrin and Varvaro among the initial five because they are out of options and if their spring training performances are decent the team will try to avoid losing them. Note that I list quite a few guys who have been mainly starters in the minors as potential depth for the pen. This is a common transition. And the guys who start in the minors are usually (though not always) more talented than those who come up as relievers. Graham and Simmons are two guys with a lot of upside who I had trouble placing in the pecking order. Graham due to his injury last year and Simmons due to his rapid climb.
Left-handed relief: Avilan and Buchter on the opening day roster. Venters will be added once he is ready.
Unlike the situation with righties, we are quite short of lefty depth in the upper minors. Thomas is the only guy with good potential among the remaining lefties likely to be in AAA. Given this situation, I think Wren will try to sign EOF or add another lefty reliever.