Tyler Clippard. (Photo by John McDonnell/The Washington Post)

Trailing by one run entering the ninth inning of the first game of Tuesday’s doubleheader, the Nationals were put in a precarious situation because of an ill-advised throw by Bryce Harper. With one out, Atlanta’s Elliot Johnson smacked a single to left field off reliever Ryan Mattheus. Johnson took a turn around first base and left fielder Bryce Harper scooped up the ball and saw an opening he felt he could take advantage of.

From left, Harper fired a the ball all the way to first base, trying to throw behind Johnson. First baseman Adam LaRoche seemed to be caught off guard by the throw, struggling to corral the bouncing ball. It skipped past him and allowed Johnson to take second base on the throwing error. Harper turned away from the play and bent at the hip, upset with the outcome of his throw.

Johnson then stole third base. Third baseman Ryan Zimmerman made a nifty play to nab Justin Upton’s ground ball and throw him out at first. But when shortstop Ian Desmond botched Freddie Freeman’s potentially inning-ending ground ball, Johnson scored and gave the Braves a crucial insurance run. The Nationals would mount an improbable comeback and score three runs off Braves dominant closer Craig Kimbrel and win the game, but Harper’s throw could be a deciding run if Washington’s ninth inning rally fell short.

Asked if he spoke with Harper about the play, Nationals Manager Davey Johnson sighed: “He knows. But he’s still going to get some comments. Could’ve been the game right there.” Who would he hear from? “From everybody.”

If Harper makes the throw, he would lauded for erasing a key baserunner late in the game. His strong arm had saved runs and even the threat of it keeps runners honest. He is second among National League outfielders with 13 assists. But the chances of success on that throw are slim. It was too risky from that distance, even with Harper’s arm strength, and Elliot Johnson likely wasn’t enough off first base to warrant the throw.

“He’s still learning,” center fielder Denard Span said about Harper’s throw. “Elliot Johnson, he took a big turn around the base. I don’t know. I’m not his coach.”

The Nationals also needed to mount a late comeback because of a rare gaffe by reliever Tyler Clippard. The Nationals were hanging by a thread all game, but when the dominant right-hander reliever served up a two-run home run to Atlanta’s Evan Gattis that put Washington in a 4-3 deficit in the eighth inning, it snapped. Clippard’s command was off; he walked two batters and allowed two hits in the inning before wiggling out of it.

Clippard entered the inning with a 2.15 ERA and 32 holds, the second most in baseball. Tuesday’s outing was only the seventh time in 28 appearances since the all-star break that Clippard has allowed a run. The right-hander has been near-automatic against every team except the Braves. He has allowed 18 runs this season, but seven have been against the Braves.

On Tuesday, Clippard walked Freeman with one out on five pitches. And after jumping ahead of Gattis, he fired an 0-2 high fastball that the strong left fielder mashed high and deep to center field. Clippard looked beside himself on the mound after allowing the home run. And inside the clubhouse after his outing, he was, too.

“I saw him in here,” said Dan Haren, who started the first game of the doubleheader. “He felt terrible. He was yelling for 15 minutes straight. He was screaming in his locker. So how many times has the guy picked us up this year in huge games. So many holds, the guy pitches six out of seven days. The guy’s been money all year. And it’s nice for us to pick him up once. I know after the game, he was going crazy, too. So he felt great about it.”