Winn didn't participate in batting practice Wednesday and Thursday due to tightness in his upper body, Derrick Goold of the St. Louis Post-Dispatchreports.
The 21-year-old still went through all other drills and could resume swinging as early as Friday, so the injury -- vague though it is -- doesn't appear to be a serious concern. Still, the Cardinals don't have much depth at shortstop with Winn and top backup Tommy Edman (wrist) banged up early in camp.