(J Pat Carter/Associated Press)

Last Sunday, Tyler Clippard needed a day off so Drew Storen, who saved 43 games last year, stepped in. Yesterday, Storen needed a day off so Michael Gonzalez set up. Sean Burnett needed a day off, so Johnson went to Tom Gorzelanny in when he needed an out with the tying run on second and a lefty at the plate.

“That speaks volumes about the talent that’s down there,” Ryan Mattheus said. “That’s big that someone can step in and do that job when Burnie needs a day off, and Drew can close games when Clip’s not here.”

Johnson believes a healthy, fresh bullpen is essential to success in a playoff race. A worn bullpen can derail a season in September — see the Braves last year. Johnson is intent on keeping his ace relievers rested. And because of the Nationals’ depth, they’ve been able to keep winning, too.

“The way everybody is out there pitching, you could put anybody in that situation,” Gonzalez said. “You could put whoever you want. That’s just how confident the bullpen is right now.

“I really feel like this bullpen, you just don’t mess with it. The confidence is off the roof. That’s the biggest, just the confidence that these guys can go out there and get it done just as easy. You got Drew Storen throwing one or two outs, you got a pretty good bullpen.”

With Storen down yesterday, Mattheus was also foisted into a major role. He retired Paul Goldschmidt and Justin Upton, Arizona’s best two right-handed hitters, with the tying run on second in the seventh inning.

Mattheus received a subtle assist from catcher Jesus Flores. Mattheus wanted to throw Upton a first-pitch slider. He shook away from Flores’s sinker call, and Flores put down the sign for sinker. Another shake, another sinker.

“Flo wouldn’t let me throw anything else,” Mattheus said. “He kept putting the sinker down there.”

Mattheus threw the sinker inside, which kept Upton honest. When he missed with a pitch later in the at-bat, down the middle, Upton just missed. He would ground out to shortstop to end the inning.

Flores “came back to me after Upton hit the groundball to shortstop,” Mattheus said. “He said, ‘That’s why we need to throw the sinker. Once you make the mistake middle, it’s alright if you went in there once.’ Flo had a good plan.”

In the ninth, after three days off, Clippard dusted the Diamondbacks in five pitches. He said he felt much better after the break, which started when Gio Gonzalez threw a complete game in Houston. “I’m not afraid to ask for a day if I need it,” Clippard said. “If I don’t feel good, it’s better for the team for me not to be there.”

And, because of the Nationals’ deep bullpen, he can afford not to be.