Almost immediately after I pushed "publish" on that last post, news came across the interwebs that the Pirates had agreed to a one-year deal with Jeff Karstens. Bill Brink at the PG is reporting that it's a one-year deal worth $2.5 million, which you may note is actually $600,000 less than he made with the Pirates last year. A big reason the Pirates non-tendered him earlier this off-season was that they didn't think he'd be worth the raise he was due through the arbitration process (~$4 million), so this is a pretty nice deal for a Pirate team that badly needs pitching depth.
In fact, at $2.5 million I'd be mad if the Pirates didn't bring Karstens back. Over the last two seasons, Karstens has evolved from a fringe big leaguer into a pretty useful arm. In both 2011 and 2012, he increased his strikeout percentage and decreased his walk percentage to the point that his K/BB ratio last year was an excellent 4.40. The two problems are that his stuff isn't overwhelming, which means that there are plenty of doubts about his ability to repeat his two-year mini-breakout, and that he's not durable at all*.
While you could argue that the Pirates' non-tendering of Karstens was justified, that still didn't mean that it made a whole ton of sense. As I've been saying ad nauseum, the Pirates have depth problems in their rotation and 90 or 110 or 130 innings of Jeff Karstens is 90 or 110 or 140 innings that don't need to be thrown by someone that's not a Major League pitcher. When the Pirates signed Russell Martin, I wrote that while Martin might be worth $17 million to two years to some teams, that I wasn't sure the Pirates were one of those teams. You could make the opposite case about Karstens: that he wasn't necessarily going to be worth $4 million, but that he would've been worth $4 million to the Pirates. Now, we don't have to worry about that.
All of that being said, I think the Pirates could really still use Francisco Liriano or Shaun Marcum in the rotation. Karstens helps things out a bit, but he still only contributes maybe half of a rotation spot to a team that has, at the absolute most, three Major League capable starters right now. Bringing Karstens back is a start and it's a win for Neal Huntington at this price, but I still think there's more work to be done.