Baez was removed from Wednesday's game against the Giants after the ninth inning due to left side tightness, Derrick Goold of the St. Louis Post-Dispatch reports.
Baez popped out in the bottom of the eighth inning and was lifted from the contest before the game went to extras. The Cardinals are considering the outfielder day-to-day for the time being, but it's unclear whether he will be sent for medical imaging. Baez was hitless in four trips to the plate Wednesday before exiting.