WASHINGTON – The Washington Nationals postponed Monday night’s game against the Atlanta Braves following shootings at the nearby Navy Yard.

The game was rescheduled as part of a day-night doubleheader on Tuesday.

The postponement was announced shortly after 3 p.m., about four hours before scheduled start. Police activity was visible around the stadium, and sirens could be heard throughout the afternoon.

Players from both teams were in the clubhouses at the time of the postponement along with stadium employees.

ROYALS: Top pitching prospect Yordano Ventura will make his major league debut for Kansas City on Tuesday night when he takes Danny Duffy’s place in the rotation against Cleveland.

Duffy has been experiencing some inflammation in his surgically repaired left elbow, and the Royals decided to give Ventura the start in a critical series with playoff implications.

With a fastball that touches triple-digits, a hard slider, decent change-up and knee-buckling curveball, Ventura has shot through the Royals’ system.

Ventura began the season at Double-A Northwest Arkansas and advanced to Triple-A Omaha, where he was 5-4 with a 3.74 ERA.

METS: Injured ace Matt Harvey has been examined by Dr. James Andrews for a second opinion on his right elbow.

The 24-year-old right-hander, diagnosed with a partially torn ulnar collateral ligament, hopes to avoid reconstructive surgery, which would sideline him for 2014.

The NL starter in this year’s All-Star game at Citi Field, Harvey is 9-5 with a 2.27 ERA and 191 strikeouts in 178 1-3 innings.

MARINERS: Felix Hernandez, is not ready to return to Seattle’s starting rotation. He threw a bullpen session Monday in Detroit, but Hisashi Iwakuma will start against the Tigers on Wednesday night.