It's not known what kind of deal Harris is looking for. However, the parties have not had serious talks yet. Harris and general manager Jim Bowden were unavailable for comment.
Harris, who will be in his second year of arbitration, has been the Nationals' best player so far in the second half. He is hitting .304 with a team-leading four home runs and 15 RBIs entering Thursday's action.
Overall, Harris has a .248 batting average with a career-high nine home runs and 28 RBIs.
A backup by trade, Harris has been filling in for injured players such as outfielder Elijah Dukes, shortstop Cristian Guzman and third baseman Ryan Zimmerman.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.