Walls (undisclosed) was removed from Monday's game against the Tigers in the third inning, Marc Topkin of the Tampa Bay Times reports.
Walls missed time last week due to a left hamstring injury, but it's unclear whether his removal from Monday's game is related to that same issue. Oliver Dunn will operate at shortstop in place of Walls for the rest of the contest. The Rays should provide an update on Walls during or shortly after the game.