While the rate of players successfully returning from Tommy John surgery is higher than ever, so is the rate of players undergoing the surgery in the first place. A tear of the UCL (ulnar collateral ligament) still requires at least a year of rehabilitation and recovery, and remains as one of the most devastating injuries in all of sports. The mere thought of elbow pain is enough to strike fear in most pitchers' hearts, as is the idea of visiting the infamous Dr. James Andrews.
Thus, it makes sense that the folks at MLB Trade Rumors last week released a model for predicting Tommy John surgeries. With the number of pitchers going under the knife at an all time high, attempting to gauge which players are most at risk is a worthy endeavor. The pitchers the model predicts to be at the highest risk are Brandon Morrow and Josh Tomlin; the lowest, Eric Stults and R.A. Dickey (makes sense, given Dickey does not possess a UCL).
I'd suggest reading through all of the model's various aspects to get a thorough idea of what goes into it. In short, the model uses several variables, including things like consistent release points, days lost to arm injuries, and previous Tommy John surgeries to generate its predictions. Other factors like number of hard pitches thrown and even handedness (right-handers undergo the surgery at a slightly higher rate) are also included.
Which Yankees are at the highest risk? Let's have a look:
Unfortunately, three of the Yankees best pitchers, Masahiro Tanaka, Nathan Eovaldi, and Luis Severino, are projected as the most likely to undergo Tommy John surgery in the future. It should be noted that the percentage at the bottom of the graph does not represent the chance that a pitcher will require Tommy John. Rather, it measures each pitcher's risk above average. Eovaldi and Tanaka both have a Risk+ figure of 90, meaning that they are 90% more likely than the average pitcher to need Tommy John surgery.
Why would the model consider Tanaka and Eovaldi to be at such high risk? Well, in fact, the model doesn't exactly think they are anywhere near locks to undergo the surgery. While they are the riskiest pitchers among the New York staff, the model only assigns each of them a 3% chance of undergoing Tommy John. So while Eovaldi and Tanaka may rank, respectively, 29th and 31st in all of baseball as far as Tommy John surgery risk, their absolute chances of facing the surgery are low.
Still, it makes sense that the pair of Tanaka and Eovaldi tops the Yankees' list of risks. Eovaldi threw 1,298 hard pitches (defined as four-seam fastballs, two-seam fastballs, and sinkers) last year, is right-handed, and has undergone Tommy John in the past, all of which send up red flags. Tanaka, of course, has a partial tear in his right UCL, so he intuitively is among the riskiest Yankee hurlers. The fact that he's lost significant time to the disabled list because of recent arm injuries is also quite poor in the model's eyes (and anyone's eyes, really).
Two of New York's other best young starters, Severino and Michael Pineda, place highly on the list. Pineda also threw over 1,000 hard pitches last year, and has dealt with his share of arm injuries, most recently forearm tightness. With regard to Severino, it's simply unpleasant to think about the young, promising starter in terms of Tommy John risk. As we've seen with brilliant young pitchers such as Jose Fernandez and Stephen Strasburg, however, sometimes, the baseball gods just aren't fair.
Interestingly enough, pitchers like Ivan Nova and CC Sabathia are seen as relatively less risky. Despite having thousands of innings and pitches on his barometer, Sabathia has plenty of things going for him, according to the model. The fact that he's 35 actually plays in his favor, as players that can make it this deep in their career are often of the workhorse variety. He's also left-handed, and has had no recent arm troubles, leading the model to deem Sabathia as 122% less risky than the average pitcher. Nova's risk is above average, but his 30% Risk+ mark still seems encouragingly low, given that he himself is a Tommy John survivor.
So the Yankees don't seem terribly likely to have a pitcher undergo Tommy John in the near future, according to the model, and let's hope that it's correct. The pessimist (or perhaps realist?) in me feels that Tanaka is much riskier than the model is able to anticipate. With all luck, however, Tommy John surgery is something that the Yankee staff won't have worry about next season.