I think I shall coin a brand new phrase: "You can never have enough pitching".
I want to begin this by saying that Chris Capuano isn't that good. That usually isn't something that you'd say to endorse a signing, but that's not the point. The point is that he isn't that bad either. Now one might say, "The pitching isn't the problem! The Yankees have Shane Greene, David Phelps, Masahiro Tanaka, CC Sabathia, and possibly Brandon McCarthy or Jon Lester!" That would be correct. It would also be correct that pitching can dry up rather quickly. Even though Yankees fans haven't been spoiled the past two seasons, they have grown accustomed to good pitching. No matter who got hurt or what happened, a random minor league signing or farm hand would be able to hold up the load for a brief period of time. Frankly, that just isn't the case with most teams. And even with teams that do have that depth, it never lasts forever. There will come a time when the pitching well runs dry.
That isn't to say it will be tomorrow, but it will come. And to prepare for that day, the Yankees should have at least eight to ten starters that they'd be at least willing to put out there every fifth day. It doesn't have to be for a full 200 innings, but 50? That wouldn't be unreasonable. Capuano is that seventh starter.
Capuano is a two-time Tommy John victim, but his last surgery was in 2009 and he's been incredibly healthy since then (Not like the Yankees would demand that many innings from him). He also has only had one season in his career where his FIP- was higher than 110, and that was way back in 2004. Other than that, his FIP- has hovered between 100 and 109. To boot, his peripherals have all been trending in an upward direction, despite his age. He has the highest strikeout rate and his walk rate remains under three per nine. His home run rate is always going to be high--he's a fly ball pitcher--but that has never hurt his numbers to the point of breaking him.
People forget that having an almost-average pitcher is pretty valuable. Which pitcher has the exact same FIP- (102) as Capuano? Tim Hudson. Tim Hudson has been worth 1.6 fWAR. It is safe to say that Capuano is worth about a win and change over the course of a full season, and would give a shave less in limited time. That's worth about $5-7 million dollars in value on the free agent market, and the Yankees could have that for a fraction of the price.
Frankly, Capuano will be cheap. He will be going into his age 37 season and he's been cut and/or traded by two teams this season, so there's obviously some risk that he'll turn into a pumpkin. And that could definitely happen. Someone would bring up this article in June if Capuano is DFA'd and say, "See! We told you so!", so hello to the people of the future and let me know that I recognize your concerns and please send me back your flying cars.
Capuano was signed for $2 million in 2014, so I would imagine that a similar salary would bring him back in 2015. The Yankees obviously have money, and they spent that kind of money on Brendan Ryan to do celebrity impressions on the bench to boost morale; I think they can spare a few bucks for the veteran. He won't be great and he could even be terrible, but he'd be a relatively cheap investment with a possibly decent return. Given all the injuries that the Yankees have endured these past few years, a cheap innings eater could be worth it.