Buried in the “Rumors and Rumblings” section at the bottom of John Perrotto’s weekend roundup column on Baseball Prospectus was an intriguing note about Joba Chamberlain. “The Yankees couldn’t move right-hander Joba Chamberlain from the rotation back to the bullpen if they wanted to at this time, because shoulder problems make it too difficult for him to warm up quickly.”
Bullpen considerations aside, I have to wonder about the veracity of this rumor. If Joba had a known shoulder problem, the Yankees would not be trotting him out there every five days. They care too much about and are too focus on Joba’s future to risk his health in the short term. A shoulder problem, however, would explain the downward trend in fastball velocity Joba has been displaying since his August 2008 injury.
One of the logical fallacies of the B-Jobber argument is that Joba could go from throwing 91 mile-per-hour fastballs, as he was last week in Texas, to throwing 98 out of the pen. That simply isn’t true, and right now, this rumor puts into print something many fans have been wondering about Joba. For now, it is simply a rumor, but we’ll keep our eyes on it.