Nationals third baseman Jerry Hairston Jr. dives in vain for a ball hit by San Diego's Logan Forsythe for a single. (Nick Wass/Associated Press)

Jordan Zimmermann has learned more than he would like this season about the razor-thin margin for error that a sputtering offense provides. The lesson came again Saturday in two excruciating ways. It came throughout the afternoon, as the Washington Nationals either did not create scoring chances or wasted them. And it came in one fleeting moment, as quickly as Jayson Werth could stop, start and watch a ball bounce off his glove.

In a 2-1 loss to the San Diego Padres before 19,159 at Nationals Park, the Nationals’ bats went silent again, collecting five hits against Padres right-hander Tim Stauffer and two San Diego relievers. The Nationals’ offense has not scored many runs for any of their pitchers, but the dearth of runs with Zimmermann pitching borders on negligence. And yet, Laynce Nix’s solo home run in the seventh inning still may have been enough to give Zimmermann a win he deserved, if not for one misplay of a difficult-but-catchable ball by Werth.

For the fifth straight start, Zimmermann (2-6) allowed fewer than two runs in at least six innings; the Nationals have lost the last three. The Nationals have scored 3.13 runs per nine innings while Zimmermann has occupied the mound, and he is 1-4 in seven quality starts.

“I don’t know what it is when Jordan pitches,” Werth said. “I feel like we just get on our heels a little bit.”

Zimmermann, stone-faced and steady, has not allowed the lack of support to affect him. Saturday, he yielded only five hits and a walk in six innings, striking out four. “I just try to go out there and give the team a chance to win, and I felt I did that today,” he said. “The bats just weren’t there.”

Nationals right fielder Jayson Werth can't get to a ball hit by the Padres' Blake Tekotte that went for a triple during San Diego’s two-run fourth inning. The Padres won 2-1. (NICK WASS/ASSOCIATED PRESS)

Owing to some combination of minuscule run support, bullpen shakiness or defensive letdown, Zimmermann has not won a start since May 1. Saturday, the Nationals’ latest offensive shutdown doomed him, along with three consecutive hits he gave up in the fourth inning. And the most crucial hit still could have been an out.

With two outs in the fourth, Chase Headley dumped a single into left field. Up came Blake Tekotte, who was making his first major league start. He smoked a line drive to right field that sent Werth racing to the warning track.

Werth sprinted back, looking over his shoulder at the warning track. He lost the ball for a split second and stutter-stepped before he realized it was still sailing. He awkwardly restarted and, before reaching the wall, reached out his arm. The ball deflected off his glove.

“If you make it, it’s a really good play,” Werth said.

He leaped and bounced off the wall before he retrieved the ball and fired it back into the infield. Tekotte had time to race around to third for a triple, and Headley scored the game’s first run. When Kyle Phillips followed with a solid single, the Padres took a 2-0 lead.

Nix launched a homer off Stauffer in the seventh, slashing the deficit to one run. When Jerry Hairston led off with a double to left center in the eighth, the Nationals had one more chance to score, which only turned into a showcase of their offensive woes.

Manager Jim Riggleman sent to the plate pinch-hitter Matt Stairs, figuring a groundball to the right side could move Hairston, and a drive to the gap could tie the score.

“I was confident Matt was going to get it done there,” Riggleman said.

Quickly, it became clear he wouldn’t. He looked at two strikes from Mike Adams to fall into an 0-2 hole, then flied to center. Adams struck out Rick Ankiel swinging. Ian Desmond looked at three strikes, the third of which, replays showed, sailed well outside. Either way, the rally fizzled.

It was not the first chance the Nationals wasted. With one out in the first, they drew three consecutive walks, loading the bases for red-hot Michael Morse, who had ended Friday’s game with a game-winning homer on the first pitch of his at-bat. He swung at the first pitch again, only to ground into a 4-6-3 double play.

Those kinds of moments have haunted the Nationals. They dropped to 5-10 in one-run games, and they’re averaging 3.8 runs per game. They have now played 43 games without Ryan Zimmerman, their best player, and first baseman Adam LaRoche has been either ineffective or out of the lineup due to injury.

“That’s not an excuse for what we’re doing as a ball club,” Werth said. “Don’t need to look very far. I haven’t been getting the job done myself. But we got to turn it around.”