The Yankees’ bullpen has been a strength for many years running, but perhaps 2013 could be the most vulnerable it has been in years. Mariano Rivera has defied the odds forever, but at some point, his skills are due to diminish. Unlike the past, Rivera is coming back from serious knee injury, which raises additional questions. David Robertson is undoubtedly one of the best relievers in the game, providing solid backup for Mariano. However, after that, things get a bit more iffy. Despite Joba Chamberlain returning relatively strong from Tommy John surgery in 2012, he only threw 20.2 innings, so he’s not quite out of the woods yet. From there, it’s Boone Logan, David Aardsma, Clay Rapada, and Cody Eppley; all with question marks of their own. Don’t get me wrong, it’s a good bullpen as constituted, but with the departure of Rafael Soriano, the reliability has decreased significantly. If Brian Cashman decides to, there are still some viable options to pursue in free agency.

Of the relievers still unsigned, the two biggest available names are Francisco Rodriguez and Brian Wilson. I suppose Jose Valverde is a big name too, but I wouldn’t touch him. Anyway, the Yankees are plenty familiar with K-Rod during his Angels days, while former Giants’ closer Wilson  is returning from Tommy John surgery.

By traditional metrics, Rodriguez did not have a good 2012, posting a 4.38 ERA. It was by far the highest ERA he’s ever posted, but there are plenty of reasons to believe in K-Rod in 2013. Some of his are inflated thanks to an atrocious four appearance run in late July, during which he allowed 10 runs in 2.2 innings. Take that little spurt out, and his ERA on the year is down to 3.25. Furthermore, he may have been the victim of some bad luck, posting a 12.3 HR/FB%, up 5.8% from the year before and above his 8.3% career mark.

There are risks to K-Rod, of course. He just turned 30, and there is some evidence of diminishing stuff. Although his fastball velocity increased 1.5 MPH in 2012, batters made contact against him at a higher rate than ever before while swinging at fewer pitches. This led to a decrease in his K/9 (9.92 in 2011, 9.0 in 2012). He still strikes out plenty of batters, but it is something to watch for.

Wilson was one of the best closers in baseball from 2009-2010, regressed a bit in 2011, and then missed just about all of 2012 after undergoing Tommy John surgery. Given the general success of the surgery nowadays, there is reason to believe he’ll come back strong. Still, though, there’s always a chance he isn’t the same. The Mets have already seen him throw off a mound, meaning he’s very far along on his rehab progress already.

Both K-Rod and Wilson are likely to receive one year deals some time soon. Rodriguez should be able to find something guaranteed, while there is always a chance that Wilson may only get a minor league deal with major league roster bonuses and incentives.

Personally, I’d go for Rodriguez. In my opinion, he’s a bit of a safer bet than Wilson. Either of these pitchers would slide in nicely into the 6th or 7th innings with Joba, creating a really nice bridge to Rivera.

I don’t anticipate any moves to bolster the bullpen, as it the priority really is the DH slot and bench. Plus, the Yankees do have some good options in the minors such as Mark Montgomery. It wouldn’t hurt to have some insurance in the form of Rodriguez or Wilson, but perhaps the cost simply outweighs the benefit of who the Yankees can recall from within.

Photo by Rich Anderson [CC-BY-SA-2.0], via Wikimedia Commons