Eager to talk privately on opening day at Chicago’s Wrigley Field, Washington Nationals Manager Davey Johnson asked me to follow him to a tool-shed sized office.

During spring training, Johnson said the Nationals, who had never finished with a record above .500 since moving to the District in 2005, should make the playoffs this season. He punctuated his buzz-worthy comments with this zinger: “They can fire me” if the Nationals miss the postseason.

“I meant every word of it,” Johnson said before the Nationals began the season by defeating the Cubs. “Hey, it may sound crazy, but you know me. You know I’m not going to say it unless I believe it. I like my team. I like it a lot. And you know what? We’re gonna have some fun.”

Johnson and the Nationals are having a lot of it. Led by their 69-year-young field boss, the surprising, injury-overcoming Nationals are atop the National League East.

Despite a season’s worth of roster juggling (sending 12 players to the disabled list before June is even more confounding than a Gio Gonzalez curveball), batting order shuffling and bullpen reorganizing in the first two months, the Nationals haven’t broken stride.

“No excuses,” General Manager Mike Rizzo said recently. “Davey doesn’t believe in ’em.”

He never has. Not while guiding the Cincinnati Reds and Baltimore Orioles to division titles and leading the New York Mets to a World Series championship. During those good times, Johnson proved he could match wits with the best of his counterparts. With the Nationals, Johnson is showing something new: He has never been better.

He’s pushing the right buttons (the Ian Desmond-Steve Lombardozzi change at the leadoff spot was among his many correct moves) while waiting for the return of key players such as cleanup hitter Michael Morse and closer Drew Storen. But Johnson’s difference-making contribution goes way beyond knowing when to double-switch.

One of the all-time great players’ managers, Johnson has the Nationals believing they can win. His unwavering support for his players — he’s even standing up for demoted closer Henry Rodriguez — has created a fast-acting bond between them and him.

Obviously, the Nationals haven’t won anything yet, and there’s still more than four full months to play in the regular season. After experiencing only bad luck on the health front, the ballclub sure could use some of the other kind.

Whatever happens the rest of the way, though, Johnson plans to stick by his comments about the Nationals’ potential. It’s as clear to him as Bryce Harper’s imminent collision with superstardom.

“What’d I tell ya?” Johnson said before the trip, reminding me of our earlier conversation. “Nothing we’ve done has” surprised him.

“I knew what I saw [in the team]. I’ve been doing this for a little while now.”

Rizzo provided a concrete-strong foundation of pitching. With the Nationals’ deep, power-armed starting rotation and bullpen, “I knew that would be a pretty good place to start,” Johnson said.

He also figured his bullhorn lobbying to liberate Harper from the minor leagues would at least accelerate the process a little. Harper’s production prompted Johnson to move him up in the batting order, but Johnson had always hoped the 19-year-old would make the decision easy for him. “I think he’s gonna be okay,” Johnson said before smiling wryly.

Harper, Lombardozzi and Tyler Clippard (the top-notch setup man has also taken on part-time-closer duties) are on the Nationals’ long list of step-up performers. With all their injuries, the club needed new heroes to emerge. Although Johnson doesn’t count himself as one of them, he should.

Always calm in a storm, Johnson projects the type of we’ll-be-fine steadiness that’s perfect for the up-and-coming Nationals. His strong playing résumé (Johnson was a four-time all-star) and my-door-is-always-open policy only help to increase Johnson’s stature in the clubhouse.

“Davey has been successful at everything he has done in the game,” Rizzo said. “Believe me, our guys understand that.”

They also appreciate Johnson’s tell-it-like-it-is honesty.

Johnson stuck with Rodriguez in the closer’s role much longer than many Nationals fans probably would have preferred. He defended Rodriguez while speaking with reporters and encouraged him in the sanctuary of the clubhouse. Even after shifting to a closer by committee, Johnson hasn’t given up on Rodriguez. He doesn’t turn his back on players — unless they give up on themselves.

That’s one of the most important things I learned about Johnson when he managed the Los Angeles Dodgers (1999-2000) and I covered the club for the Los Angeles Times: He’s fiercely loyal.

“Gotta be that way,” he said. “I gotta be with [the players] because I live with them. They have to know they can count on me. That’s the only way it works.”

In the past, Johnson’s players-first approach has gotten him into trouble with management. His Dodgers superiors believed Johnson was too easy-going with players.

Rizzo is fine with Johnson’s style. Not surprisingly, so are Nationals players.

“You know where Davey is coming from,” Desmond said. “You know it makes sense to listen to him.”

The Nationals have the right man for the job. And the real fun will be in seeing how far he can take them.

For Jason Reid’s previous columns go to washingtonpost.com/reid.