Houser was removed from Tuesday's game against the Red with an apparent arm injury, Alex Pavlovic of NBC Sports Bay Area reports.
Houser's arm began giving him trouble after he made a pitch during the second inning, and manager Tony Vitello made the call to take him out of the game immediately afterward. It's unclear what exactly the right-hander is dealing with, but the Giants should provide an update on his status after they get a closer look at him.