All gates for the originally scheduled 7:05 game will open 1 1/2 hours after the last out of the 1:05 game or at 6, whichever is later. The two games against the Braves will require separate admission.
Fans with game tickets to Monday's postponed contest may use their original tickets for the 1:05 makeup game. Those unable to attend the 1:05 game can exchange their tickets for any remaining home game during the 2013 regular season or any Value Game during the 2014 regular season.
Both the Nationals and Major League Baseball decided to postpone the Monday night game.
"There are a lot of [logistics] that go into cancelling a game for these reasons. We have to be in contact with federal authorities and the state D.C. authorities to have a coordinated effort," Nationals general manager Mike Rizzo said. "And then whenever you cancel a game, MLB is involved and we have to go through the correct procedures for that."
As of the latest announcement, police said at least 13 people are dead and others wounded after a shooter opened fire at the facility on Monday morning.
"All of us here in the Nationals organization were deeply saddened to learn of the tragic events that occurred this morning only a few blocks from Nationals Park," the team said in a statement. "Our thoughts and prayers go out to the victims and their families.
"The safety of our fans is our utmost priority. As we have throughout the day, the Nationals security personnel will continue to work closely with all levels of law enforcement to reinforce the already high level of security in place at Nationals Park."
The tragedy at the Navy Yard took place at around 8:20 a.m., according to reports. As of 12:30 p.m., according to Nationals manager Davey Johnson, he and the players were "cleared to go to Nationals Park," but that didn't mean the game was on. After receiving the message, Johnson said he was going to "wait a while" before heading to the park. At 3:12, the Nationals announced that the game was postponed.
Haren was already at Nationals Park when the announcement was made to postpone the game.
"A lot of the older guys were texting back and forth after we heard about the tragedy," Haren said. "We were just trying to figure out the best thing to do and it was obvious to all of us -- that was to cancel the game in respect to all of the victims and their families. Two, it's really not a safe place to be tonight, with the situation on how it's moving. It really hasn't come to an end yet. It's unsafe for fans, it's unsafe for us and it's disrespectful to what is going on.
"I know we are waiting basically for 16 hours to play the game. We are doing the best we can. As inconsequential as the game may seem on a day like today, we have to play baseball at some point, and that will be tomorrow.
"If the investigation is ongoing and the higher-ups don't see that area as being safe for people to come, then we'll move forward accordingly. The No. 1 thing is the safety of all the fans, all the workers, obviously the players and everyone involved and everyone that is around that lives around the area."
According to CNN, several schools near the Navy Yard were on lock down. Workers at the Navy Yard could find their families near the parking lot B at Nationals Park.
"Nobody is thinking about baseball. Baseball is a game," Braves pitcher Scott Downs said. "You look at the real-life perspective when things go on. That's the last thing I want to do or any team wants to do, especially when something is going on five minutes down the road.
"You've got to tell your families how much you love them. They come to work and a tragedy like this happens. It's hard to put into words. You just kind of got to go about your day and have their thoughts and prayers in your mind."