Unless Twins closer Joe Nathan was recently clubbed by a baseball bat, fell down a flight of stairs or was in an automobile accident, his complaints of shoulder soreness likely can be largely discounted.
Reports of his condition center around supposed tenderness or sensitivity at the acromioclavicular joint -- the relatively stout, swiveling skeletal connection between his collar bone and shoulder. Though his soreness is real, if it were serious it would almost have to be the result of blunt trauma.
Blunt trauma -- resulting from potentially crippling impact -- accounts for nearly all manifestations of severe joint failure regarding the "AC joint." Because no blunt trauma has been reported, Nathan's injury almost certainly is more likely attributable merely to a mild strain after the offseason layoff.
Nathan likely will respond favorably to nonsteroidal anti-inflammatory medications, cold pacts and a carefully measured regimen of rest and mild excercise, including throwing. Various camp reports indicate Nathan is throwing with a normal motion, an activity he must keep up to prevent stiffness.
Expect Nathan to be fully ready to throw without limitation before opening day.