Parker didn't pitch in Wednesday's Grapefruit League against the Marlins as anticipated due to neck stiffness, Spencer Nusbaum of The Washington Post reports.
Manager Dave Martinez said Parker initially reported the issue Tuesday and is now feeling a bit better, but the team decided to keep him out of action Wednesday as a precaution. The Nats will likely wait until he's back to 100 percent before sending him back on the mound in a Grapefruit League game.