For Masahiro Tanaka, Injury Is About His Mechanics, Not His Splitter

Will Carroll@injuryexpertSports Injuries Lead WriterJuly 11, 2014

New York Yankees pitcher Masahiro Tanaka delivers to Boston Red Sox's Mike Napoli in the ninth inning of a baseball game, Saturday, June 28, 2014, in New York. Napoli hit a solo home run to right field on the pitch and the Red Sox won 2-1. (AP Photo/Julie Jacobson)
Julie Jacobson/Associated Press

Masahiro Tanaka may have been a high-priced addition to the New York Yankees last offseason, but he's been an invaluable pitcher through the first half of the season. With CC Sabathia out for this season with knee problems and several others lost to injury, Tanaka has carried the team on his unhittable splitter. Now, his arm has come up sore and perhaps broken under the load.

The Yankees' team physician reviewed the images and examined Tanaka in Seattle on Thursday, finding a small sprain of the UCL, as noted by Sweeny Murty of WFAN. My sources tell me that the tear is very small, under 10 percent, which is below the normal threshold for surgery, which is somewhere between 25 and 33 percent. Tanaka also had some small osteophytes in his elbow, which is common.

No sprain is good, but this is far from the worst case. Tanaka will have a PRP (platelet rich plasma) injection and rest for a time before starting a rehab throwing program.

If the tear does not heal or gets worse, Tanaka would be a candidate for Tommy John surgery. The UCL does often repair itself from small tears, so catching this early can be considered a positive. He is definitely going to be high risk for the near future and will have to be handled carefully. One option the team will have is to do regular checks on the area, either with MRIs or with diagnostic ultrasounds. 

There is no clear timeline for his return. The Yankees are likely to be conservative, but without Tanaka and Sabathia, the Yankees pitching is very thin.

Tanaka himself will likely drive the return date based on milestones in the rehab process. As he passes certain milestones, such as long toss and throwing from a mound, responding without setbacks, he'll be allowed to push forward. He could miss as little as 15 days, but it is more likely that this could go four to six weeks. 

One of the major questions was why Tanaka was sent to Seattle rather than back to New York. Dr. Chris Ahmad, the Yankees' team physician, was in Seattle to attend the annual AOSSM convention. Dr. Ahmad is a board member and has made major presentations in the past, such as performing a shoulder labrum repair live for attendees at last year's meeting. (He was live; the shoulder was not, as you can see in the attached picture.)

Rather than wait or send Tanaka to another surgeon, it was simpler to send Tanaka to Seattle. Many of the other top surgeons in sports are present at this conference, so if a second opinion is requested, it could likely be handled quickly.

One of the main questions that will be asked about Tanaka's arm injury is whether changes to his workouts and frequency of outings caused problems. It is well-known that Japanese pitchers throw less often, usually once a week, and have extensive between-start routines. They also tend to throw more pitches. 

Daisuke Matsuzaka had difficulty adjusting to the American style and injured his elbow, with many blaming the changes for his problems. Yu Darvish has been more successful, but the Rangers have eliminated several of the pitches he featured in Japan, though he will occasionally bring them out in situations. Tanaka has a more limited repertoire, being far more reliant on his dominant splitter both in Japan and in his time with the Yankees.

Japanese workouts are often as inexplicable as their musical tastes. (That band, Momoiro Clover Z, is Tanaka's favorite.) Pitchers will regularly throw in the bullpen in between innings and will often go to the pen for work after they are removed from starts, especially in unsuccessful starts. 

Tanaka did, like many pitchers, have an extensive workload in Japan when he was young. He was pitching for Rakuten at age 18 after a celebrated high school career.

While Japanese pitchers make fewer starts, they tend to throw more pitches. Tanaka wasn't injury-free in Japan, having a couple episodes of shoulder fatigue that cost him starts, especially in 2009 and 2010. He came back well after these problems and was dominant in 2013. 

Research that I did with Nate Silver in 2004 showed that pitchers younger than 24 were more likely to be injured, so this is a bit worrisome, though the Yankees surely understood this when they purchased him. 

Another question that the Yankees and Tanaka are going to have to determine is how damaging his splitter is. The pitch has long been thought to have a higher cost than other pitches, but the entire idea of pitch cost has largely been reduced by current research.

Chris O'Leary, a top researcher, does a good job debunking this theory in this thread. I asked him what he thought about Tanaka's splitter and overall. He told me:

"Some will point to Tanaka's use of the splitter as a red flag. However, I've yet to see convincing evidence of a correlation between arm problems and the splitter. If you look at Tanaka's mechanics, you can see evidence of the timing problem that you tend to see in high pitching elbow guys and that eventually overloads the elbow and the shoulder."

As stated earlier, Tanaka used the same pitch repertoire in Japan for years without injury, so it's difficult to say that this should have suddenly become a problem unless it's one of wear-down. That means there's no easy answer as to why he has suddenly hit the disabled list.

It's not Tanaka's pitches. It's not that he's Japanese. Instead, it's as simple as it is for so many other pitchers: poor mechanics. It appears that he is just another injured pitcher on the long list we have of those in 2014. As dominant as he has shown he can be, he and the Yankees will have to figure out how to keep him healthy enough to use it.


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