We are getting very close to catchers and pitchers reporting. We might have one or two moves of significance until that point, but I'm going to assume that our team is essentially what we have in front of us. That being said, I'm going to take a broad look at every position to seem what we have there, both now and going forward. First up are the catchers.
The MLB average wOBA for a catcher last year was .312.
Beef Castle is the definite starter next year. He's projected by BJ to have a wOBA of .318. I like him a pretty good deal: his minor league numbers indicate that he is ascending, he improved over the course of the season, and his defensive game-calling abilities are vastly underrated and overreported. Not an area of concern. Steve Clevenger's projection seems incredibly optimistic. I'm not sure I expect an wOBA above .285-.290. If he does reach .310, he becomes a very useful backup/utility guy; it's also the only he stays on the roster. Some people believe he played all of 2012 hurt, but that's either false or stupid (take your pick). Dioner Navarro is 5 years removed from being useful. He's the de facto backup, though he can't hit and can barely field so who knows how long it'll be until he's usurped by Clevenger or someone else.
Juan Apodaca is a 26-year old journeyman who put up very nice numbers in AAA last year. He's been with 4 organizations and never reached the bigs. I don't understand why: he's not old, he's walked at every level, and the very few scouting reports I've seen on him indicate he's not terrible behind the plate. He's got low power, but that's no game breaker: he maybe deserves a backup role somewhere but it won't be with the Cubs – they released him last year (he's with the Rangers now). I include him only because he was the primary AAA guy this year: the other guy (that wasn't Castillo) was the abortive Brian Esposito. I haven't seen his release notice on mlbtr so I assume he's still with the club: he's 33 and can't hack it at AAA. Blake Lalli was also booted. The Cubs had 4 primary catchers on the AAA roster last year and none of them will be back.
Michael Brenly is the "favorite" to break camp with the AAA squad (if Clevenger isn't waived, clears, and accepts). He is the son of Bob Brenly, which is the only reason he was drafted. Since then, he's been an unspectacular, slow-moving catcher. I have no reason to believe he'll ever contribute at the MLB level. Luis Flores put up a .572 OPS as a 25 year backup in AA last year.
Micah Gibbs might be a backup one day, maybe? He walks and he's not particularly old for his level (I mean, he's not a prospect level, but he's not completely worthless yet). He's got no power and for a 3rd rounder has disappointed. Se la vie…Chad Noble was so bad last year that I couldn't even include him on this list. Rafael Lopez is too old for this level, but has been a solid performer so far. Catchers as a rule get a longer age-leash in the minors, so the book isn't entirely closed on him. He's got mediocre gap power, which for a catcher is pretty good.
Yaniel Cabezas had an OPS under .550 and thus didn't qualify for my list, because he isn't a baseball player. Sergio Burruel has youth on his side, but he's been in the organization for 4 years and has never slugged above his OBP. Chadd Krist inexplicably sounds like the name of a porn star to me. He had a very nice season in 2012 and should start the year as the A starter, or maybe the A+ co-starter.
Wilson Contreras is young and adequate at Boise this year. He also had a 47% CS last year, which is probably unsustainable. He's been in the organization for 4 years and has always been average to middling with the bat, but that's no dealbreaker at all. Lance Rymel was a 28th round draft pick in the 2012 draft and got embarrassed in his 25 games. His BABIP was under .200 so he's a fair bet to look better next year, but he has some definite work to do if he wants to stick around. Carlos Escobar is another 2012 draftee (15th), and he acquitted himself quite well. He'll be 22 next year, and should grab the bulk of the starts for the club next year if not promoted to A outright.
Justin Marra is become Youkilis, destroyer of pitchers with poor control. He got a late start to his career after being drafted in 2011, but embarrassed the rookie league much like Vogelbach did (albeit in a much different way). He had a .397 BABIP, so he's a serious regression candidate (as is the fact that he very likely just took the walks given to him), but you couldn't ask much more from a guy in his first taste of baseball. Hits doubles, and walks, what's not to like? Alberto Mineo is 17 and has 62 career PA. I'd be lying if I told you I knew anything about him.
I'm not going to do FRk, because it's so far from my periphery.
The Cubs don't have any real breakout candidates anywhere near ready to hit the majors. Depending on how you feel about Clevenger, you might not even have great depth at the major league level. I think that there are a few fringey-prospects in the deep minors (Marra, Escobar, Contreras) but absolutely no one that I'd feel projecting to ever start for the Cubs in the next 4-5 years.