Walker (hip) is out of the lineup for Monday's game against the Marlins.
Walker will take a seat for the second day in a row after he was removed from Saturday's 4-2 loss to the Orioles due to right hip tightness. LaMonte Wade will pick up the start at first base Monday in place of Walker, whom the Astros are viewing as day-to-day after he was able to take part in baseball activities Sunday.