Montgomery is out of the lineup for Sunday's game against the Astros after fouling a pitch off his right shin late in Saturday's 4-1 loss.
The 24-year-old sat out Tuesday after fouling a pitch off the same shin Monday, and manager Will Venable said that Saturday's incident occurred just above the previous one, per Scott Merkin of MLB.com. Montgomery was able to finish his plate appearance Saturday but will miss at least one start due to the injury, though he's expected to return to action Monday versus the Yankees, per Merkin. Luisangel Acuna will start at shortstop in Sunday's series finale.