As has been the norm over the past few years, it appears the Yankees will be carrying 13 position players and 12 pitchers on their 25-man roster. In some ways, this is a luxury the Yankees can afford. As we mentioned earlier this week, the Yanks have a bit of roster flexibility on the offensive side, with backups Duncan and Betemit able to play multiple positions if needed.

If the team is going to carry 12 pitchers, some will argue that one of them has to be a lefty. I’m not quite sure I buy into that logic. There are a couple of questions that go along with this, which I’m not sure I’m able to answer.

First, what is the purpose of having a lefty reliever? Well, like having a lefty in the rotation, one purpose is to keep the opposition off balance. However, I’m not sure how much of a difference that makes. Sure, you see lefties less often than righties, but ballplayers surely see enough of them that they’re not going to be overly affected merely by seeing someone throw with their left arm.

It seems that we’ve come to the consensus of late that the purpose of a lefty reliever is to come in and face “tough lefties.” Of course, there is plenty of debate about this as well. To the Yankees, this issue might be a bit more paramount, since they see David Ortiz multiple times per year. There are other big lefties in the AL East, too, including Carl Crawford, Carlos Pena, and Nick Markakis. In addition, Matt Stairs and Brian Roberts have favorable splits vs. righties, and there’s always J.D. Drew, who could go out and have a year like he did in 2004. And then there are the other lefties the Yanks face from time to time, like Jim Thome, Travis Hafner, Joe Mauer, Justin Morneau, Jack Cust, Yankee-killer Garrett Anderson, and soon to be Alex Gordon.

So the second question is, does the value of having a better chance of getting these guys out justify a lefty reliever’s place on the 25-man roster, and more specifically, on the 12-man pitching staff? After all, none of these aforementioned lefties hit back-to-back in their respective batting orders. This leaves few options for the deployment of a lefty reliever if there are multiple strong lefties in a lineup. You either have him face one or the other, or you have him pitch to the righty in between. And since these lefties, for the most part, hit at the front or heart of their order, you can bet the righty in the middle is going to be a masher himself.

Clearly, the overriding criteria for a lefty reliever is that he fare well against lefty hitters. Bonus points go to the lefty who can also hold his own against righties. Problem is, pitchers who fit this description are rare. Combined with the general volatility of relief pitchers, it makes the search of an effective lefty arm sometimes grueling.

Two lefty relievers remain on the free agent market: Trever Miller and Jeremy Affeldt. After seeing mediocre colleagues Ron Mahay and J.C. Romero pull down some serious dollars, the remaining two are sure to be holding out for similar deals. And while it may be tempting to pick up one of them, I don’t think either will make much of a difference.

Miller had an off year in 2007 after quite a few above-average years. A quick glance might suggest that he’s a viable bounce-back candidate — I thought the same thing when I pulled up his Baseball Reference page. However, let’s look at the numbers beyond the ERA.

The past two years, he’s struck out about a batter per inning, which is always nice from a reliever. However, this is a recent trend. Before 2006, he had never hit the strikeout-per-inning mark, though he hovered at about seven per nine for most of his career. Also, since 2000 he hasn’t allowed more hits than innings pitched. Ah, but he’s got the blemish: terrible walk rate. Or at least inconsistent. He was able to keep his walks per nine below 3.00 in two seasons — 2004 and 2006 — and he was stellar at those times. The other years, though, he’s been above 4.00. I don’t know about you, but I’ve seen enough of that garbage from our pen.

His splits against lefties in 2004 and 2006, unsurprisingly, were excellent. He even had decent splits last year, when he was pretty much crap. On his “off” years, though, he’s had trouble keeping his OPS below .700 against lefties. And, though it all, one theme remains consistent, even in his “on” years: he gives up WAY too many bombs against lefties. Doubles and bombs. Exactly what you don’t want from a reliever.

If you’re as sick of me of relievers walking everyone, you won’t even look at Affeldt. His BB/9 — even in 2007, when he had a decent year — is consistently over 4.50. He doesn’t strike out a ton of guys, either, which means that he’s allowing a lot of contact. Contact and walks. Not good. This has resulted in him allowing over a hit per inning every year of his career — except his contract year, of course. His splits are all over the place, but on the whole they’re not good against lefties at all.

I’d rather have no lefties in the pen than sign either of these guys. If Miller would accept a one-year deal, then maybe I’d consider, but it’s doubtful he’d do that. That leaves the Yanks with internal options: Sean Henn, Kei Igawa, Chase Wright, and possibly Ben Kozlowski, if they’re able to bring him back on a minor-league deal.

Henn survived the winter cuts and is out of options, so he’s likely to get the first nod. I’m not sure what the team’s plans for Igawa are, but starting him off in Scranton seems the ideal scenario. Chase Wright posted decent lefty/righty splits in AA, so there’s a chance he could serve as a bullpen lefty in the future. But, since he struggled at the AAA level, there’s little chance he breaks camp with the team.

Personally, I’d rather carry an all-righty bullpen than hand the spot to Miller, Affeldt, or Henn. It appears the Yanks are hearing those sentiments on the former two, but not on Henn. He’s probably going to have to fail at the Major League level again before the Yankees sever ties — and who knows how many games he’ll screw up by that point?

The overall idea is, why carry a lefty reliever if you can’t find any such players who can serve the purpose of having a lefty in the pen? It makes no sense to me.