Jordan Zimmerman rebounds from a string of mediocre performances to gut his way through six scoreless innings at Miller Park. (Tom Lynn/Getty Images)

Bryce Harper’s latest foray into leadership hung on the back of each chair in the Washington Nationals’ clubhouse Friday afternoon, hours before their 4-1 victory over the Milwaukee Brewers. The red-and-black camouflage T-shirts carried a message — borrowed from the movie “Red Tails” — chosen as an impassioned reminder to a team in free-fall: “To the last minute. To the last second. To the last man: We FIGHT!”

“I thought that was pretty cool motto,” Harper said. “I think it fits pretty well right now.”

After the Nationals’ beatdown Wednesday in Detroit, Harper had waded into team-spokesman territory when he pleaded for the Nationals to play with “heart” and “like a family,” urging them not to give up on the season. He delivered another message Friday like any 20-year-old might: with a T-shirt order.

Slogans and speeches only go so far, and Harper also delivered in the manner that truly matters. He went 2 for 4 and laced a solo home run into the upper deck off Burke Badenhop, providing one of many contributions that halted the Nationals’ losing skid at two games.

“He rises to the occasion pretty well, if you hadn’t noticed,” shortstop Ian Desmond said.

Pitching three hours from his tiny home town of Auburndale, Wis., Jordan Zimmermann gutted through six scoreless innings. Jayson Werth left behind his torrid July with three hits in his first game of August. Desmond created the Nationals’ first run when he doubled to center field, stole third base and scooted home as catcher Jonathan Lucroy’s throw got past third baseman Jeff Bianchi and into left field.

Other than Desmond’s self-made score, the Nationals were shut down for four innings by Alfredo Figaro, a journeyman long reliever pressed into service after Werth’s line drive drilled Brewers starter (and former National) Tom Gorzelanny on the left elbow. But Zimmermann’s performance and just enough offense gave the Nationals their fifth victory in 14 games since the all-star break.

Zimmermann punched up a 7.81 ERA over five July starts and battled a pinched nerve his neck that prevented him from pitching in the All-Star Game. Friday night, he still lacked his sharpest stuff. He allowed four doubles, yielded four walks and hit a batter. He allowed a base runner in every inning and a Brewer reached second base in four of six innings. And still, none crossed the plate.

“I was happy to put up some zeroes, get the month of July over with and into a new month,” Zimmermann said.

The Nationals’ season is still hanging from a cliff, their victory over the Brewers keeping another fingernail between safety and careening down the ravine. They are 111 / 2 games behind an Atlanta Braves team that has forgotten how to lose and 61 / 2 back of the second wild-card spot, with the Diamondbacks standing between them and the Reds. Entering Friday, Baseball Prospectus’s playoff odds calculation gave them a 0.5 percent shot to win the division and a 3.4 percent chance to get into the postseason. They are running out of time.

“We have to play real good ball from here on out to have any chance at all,” Johnson said. “I think the guys know that.”

Harper stressed togetherness and urgency, but his plea did not exactly reverberate through the clubhouse. “What’d he say?” third baseman Ryan Zimmerman replied when asked for his thoughts on the comments.

The Post Sports Live crew debates whether Mike Rizzo sending Drew Storen down to AAA Syracuse was the right move for the Nationals and the struggling reliever. (Post Sports Live)

Desmond, one of the Nationals’ most vocal leaders, had heard them.

“He’s been out there grinding with us all along,” Desmond said. “He has the right to say whatever he wants. More power to him. I like him. We need more people to speak up. He’s right. We got to play the game hard. We got to have heart. Simple as that. He didn’t say anything that was untrue. It’s good to see him come into his own.”

In Zimmerman’s view, Harper may have mistaken steady professionalism for indifference. Harper is not far removed from his high school football days. Zimmerman eschews team meetings and pep talks.

“When it comes down to it, you shouldn’t have to tell 30-year-old men who are getting paid millions of dollars to play baseball what to do or have to fire ’em up,” Zimmerman said. “I really don’t believe in that kind of stuff. I go out there every night and do everything I can to help the team win, whether we’re 30 games under .500 or 30 games over. Because that’s what I’m supposed to do. I don’t really think anyone else in that clubhouse has a different mind-set than I do.”

Johnson sided with Zimmerman. Anxiety, he believes, is the product of losing, not the root of it. “Shoot, earlier in the year my whole bench was hitting under .200,” Johnson said. “You think they’re going to be singing karaoke songs?”

The Nationals’ season remains a long way from where they want it to be. They recognize nothing can change that other than steady progress. Friday night, their starter battled through diminished stuff and their offense plugged away. It didn’t matter it came out of a 20-year-old’s T-shirt or a rote sense of duty. What mattered is, they fought.