Posted by Matt Sisson on Friday, February 27, 2009 at 11:16 am

I’ll say it right here…using Joba as a full time starter this season will end up hurting the Yankees and Joba. In an article I wrote for this publication, I detailed the plan the Yankees should put in place for Chamberlain and it was the same plan they were going to use before the 2008 season. With the addition of Sabathia & Burnett and Wang returning to the rotation, it makes more sense than it did last year. Chamberlain tossed just 100 1/3 innings in 2008 and the Yankees plan on limiting him to 150 innings in 2009, seems like a great plan now but how closely will they stick to that? His inning goal in 2008 was 140 innings…he got hurt and didn’t come close to that mark…does it make sense to tack on 10 more innings at this point? The Yankee front office also came out during the off season stating that Chamberlain would likely make 25 starts in ‘09…that number is now up to 30.

30 starts isn’t all that many but it is for a young pitcher with shoulder problems and what happens if the Yankees make the playoffs? Obviously they can use Chamberlain in the bullpen in October and go with a 3 or 4 man rotation, but what if there’s a mid-season injury? The smart thing to do would be to start Joba in the bullpen and play it safe. Joba wasn’t the same pitcher he was when he returned from a month or rest in ‘08. Using PITCHf/x data to track his pitch speed you can clearly see that he’s down about 5mph on his fastball.

Here is Joba’s pitch speed as a reliever before he was injured:

As you can see, Joba is consistently above the 96mph mark often times approaching 100mph.

Here is Joba’s pitch speed as a starter before he was injured:

The pitch speeds for his fastballs are again between 95-100mph.

Here is the pitch speed for Joba when he returned from the disabled list:

Joba is only able to reach 96mph a handful of times and this was after more than a month of rest.

I’ve also tracked his release points pre and post injury (see below).

Aside from the 4 pitch intentional walk, Joba’s release point is much closer to his body. When a pitcher has discomfort in their shoulder caused by the action of throwing a baseball, they are forced to change the way they throw in an effort to relieve the discomfort. When a pitcher develops shoulder tendinitis the joint becomes inflamed causing it to become weak and unstable. Joba’s release point since returning from injury is closer to the body and is likely due to Chamberlain attempting to keep his arm slot in an an effort to increase the stability of the joint as opposed to further away from the body where it can become less stable.

The change in release point, as well as the drop in velocity are two warning flags the Yankee organization should take into consideration. Joba will likely be better off being held back as a reliever but if the Yankees intend on using him as a starter all year long there are a few likely spots in the schedule where they can find time to skip a start or two. The first of these spots being in the beginning of the season during the Yankees home opener. The number five spot happens to fall on that day and with the Yankees spending so much money on both a new stadium and C.C. Sabathia, why not let him start the home opener in their new stadium?