Locker room sources tell us Padres players decided last night they wanted to honor the military by sporting the unis -- which they normally wear only for Sunday home games.
San Diego is home for many U.S. troops, including Navy SEALS ... and the USS Carl Vinson -- the aircraft carrier that buried bin Laden at sea.
We're told the Padres will also observe a moment of silence before tonight's game at PETCO Park to remember the victims of 9/11.
UPDATE: The Padres announced all active, retired, and veteran military personnel can get two free tickets to tonight's game. You can hear the cheers already ... "USA! USA!!"