Diaz signed a minor-league contract with the Nationals on Friday that includes an invitation to spring training, Kiley McDaniel of ESPN.com reports.
The Nationals look like they might be going the quantity over quality route in attempting to address first base, first adding Juan Yepez and now Diaz as non-roster invitees. Diaz posted an .804 OPS with 17 homers over 118 games for the Orioles' Triple-A affiliate in Norfolk but didn't see any time in the majors. He'll get a shot this spring to win an Opening Day roster spot.