Not that the Yankees will admit it so soon, but apparently Randy Johnson’s back has been acting up:
Randy Johnson will start for the Yankees tomorrow, and he said yesterday that his health was perfect. But the Yankees were so worried about Johnson’s back before his start on Tuesday that they called up another pitcher from Class AAA in case Tanyon Sturtze had to make the start for him. (The New York Times)
That’s probably a good explanation for why Johnson’s been able to keep hitting the high 90s with his fastball, but has lost his slider for the most part. I always feel that losing the breaking ball is consistent with a back injury - especially when it’s the slider that’s lost its bite, since that pitch requires a particular arm slot and angle that an injured back might compromise.
There’s another reason why pure speed on the radar gun isn’t always the best indicator of injury. With a shoulder injury you’d probably lose speed on the fastball, with a back problem you might not. Oh well, that’s my armchair physiology…