Gallo (hamstring) participated in batting practice Tuesday, Andrew Golden of The Washington Post reports.
Manager Dave Martinez noted that Gallo has also resumed fielding groundballs within the past week, though the 30-year-old still has yet to run the bases since beginning a running program June 24. Gallo will almost certainly need to embark on a rehab assignment before he can return to the Nationals, but he seems to still have some hurdles to clear before he can begin playing in minor-league games.