I'll quote myself from another thread...
Perception isn't always reality. If the media tells fans their teams pitching is bad enough times it sticks. That's not to say they can't improve because there are very few cases where you can't improve. But the talk of needing at least 2 starters to me is ignorant. I don't mean ignorant as an insult. I mean it as the actual definition of the word(lacking knowledge, information, or awareness about something in particular.). It's easy to forget this team won 97 games because they finished 3rd in their devision. Teams that win 97 games usually have pretty damn good pitching.
Simply put, you honestly aren't going to do much better than the staff they had this year realistically speaking. Even as absurd as the cardinals pitching was this year the cubs were better in a number of areas which is why they had more fWAR. The one area they realistically can improve on is the #5 starter because as mentioned it was a bit of a mess most of the year. Now setting your sights on a #5 is probably not worth your time. I think ideally you want to push Hammel to the #5.
Another thing I mentioned in that other topic is Pierce Johnson probably starts in AAA and IIRC is pitching in the AFL because he missed some time this season. What that likely means is he doesn't necessarily need a full year at AAA if all goes according to plan. It's easy to forget because he's been over shadowed by guys like Bryant and Russell but Johnson has #3 stuff. In 98 IP in AA this year he had a 2.08 ERA(3.47 FIP). His k/9 and bb/9 weren't as good as you'd like but he was coming back from an injury so that's not too surprising. If you were to slot him in ahead or behind Hendricks around midseason that is a pretty solid staff. It's not "holy shit" amazing but look at those rankings i posted at the top and imagine someone with some talent throwing say 20 starts instead of Wada/Richard/Harren/Roach.
I'm sure they will consider dealing for pitching but I don't think it is as obvious as some make it out to be. Seems to me it's more a case of it being the right price for the right player. The obvious talk will be about trading Baez and/or Castro. But I had a thought that maybe the front office has too. Typically when NL teams have to play AL teams with a DH they lose because they don't have a full time hitter that's really good enough. But the cubs do... and they are all cheap. Sure it's a bit clunky having someone as talented as Baez or Castro or whomever riding the bench but we've seen Maddon make it work. And it's also very nice protection against injury. For example, what if Russell had pulled his hammy in July instead of in the playoffs? It's nice to have someone like Baez to just slot in with no worry and you're not having to give up a ton of young talent at the deadline to replace a hurt player.
Additionally, I posted something the other day talking about the likely bump in revenue the cubs will enjoy thanks to this playoff run. In that I commented that since 2006 there hasn't been a single offseason where more than 2 pitchers got monster deals. Last offseason was sort of a typical case. You had Scherzer getting $30 mil/season. Lester got $25.8 mil. Shields got $18.75 mil/season. That seems to be a some what typical spread for the 1-3 guys. Top guy makes <x>. #2 guy makes <x-$5 mil>. #3 guy makes <x-$10 mil> or there about. If that's the case, you're going to have Grienke and Price as the two top dogs. But behind those guys you have Jordan Zimmermann, Jeff Samardzija, Bud Norris, Mike Leake, Justin Masterson, Kyle Lohse, Tim Lincecum, Cliff Lee($27.5 mil team option), Mat Latos, John Lackey, Ian Kennedy, Kyle Kendrick, Scott Kazmir, Hisashi Iwakuma, J.A. Happ, Yovani Gallardo, Doug Fister, Marco Estrada, Johnny Cueto, Wei-Yin Chen, Brett Anderson, and Chad Billingsley. That is an absurd amount of depth.
Even if Cueto, Shark, Leak and Zimmerman all are close to $20 mil which history suggests is unlikely, you still have a crap load of interesting mid rotation starters. The example I used in the other topic was say the cubs sign John Lackey to a 2 year $30 mil deal. That then buys them time with some of their younger guys like Underwood and Johnson. And in this FA market is Lackey even going to get $15 mil/season? Even if he does, you're talking about the division rival cardinals game 1 starter at that price.