Ruiz (illness) will begin a rehab assignment with Double-A Harrisburg on Tuesday, Andrew Golden of The Washington Post reports.
Ruiz will be with Harrisburg for a couple days before being activated from the injured list, likely on Friday when the Nationals begin a road trip. He hasn't played in two weeks due to a stomach bug which caused him to lose nearly 20 pounds. Riley Adams has been filling in as the Nats' primary catcher.