PHOENIX -- Zac Gallen is heating up, and it couldn't come at a better time for the Arizona Diamondbacks, who are trying to capture a National League Wild Card berth for the second consecutive year.

After tossing six shutout innings in his last start against the Giants, Gallen blanked the Rangers for five as the D-backs went on to win, 6-0, on Tuesday night at Chase Field.

The D-backs currently hold the second NL Wild Card spot thanks largely to an offense that leads the Majors in runs scored. But to get to where they want in October, they know they'll need their pitching staff to pick up the pace.

That starts with the two pitchers at the top of the rotation -- Gallen and Merrill Kelly.

"I've had discussions with them," manager Torey Lovullo said. "I've said, 'Hey, you guys are the carry tool here. We've got to have you guys go out and execute and do what you do best, and empty the tank every time you go out there.' It's very important that they pace us. They've done it before. They know what it's like to stand on that mound and execute at a high level at the most critical times. They've spoiled us with how they've done it."

Lovullo said he noticed something in how Gallen carried himself during his start against the Giants that led him to believe Gallen had found his "swagger" after a season in which he's had some fantastic starts but hasn't put together the kind of runs Arizona fans have grown accustomed to the past few years.

"I've studied him for five years, so maybe that's something that I'm imagining, I don't know, but I get the chance to see him inside the dugout, and I can see how he's interacting in the dugout," Lovullo said. "You know, when he's frustrated, he shows it, and when the swagger is there, and the walk is there, that's when he gets on those nice runs."

Gallen is a perfectionist, a pitcher who constantly tweaks his delivery to ensure everything is synced up.

Baseball, in Gallen's mind, is a lot like basketball in that it's a game of runs. Sometimes, you're on a good run of starts; other times, not so much. Being able to get the job done when you're not feeling it is important, but so is making sure you capitalize on the good times.

"When you're feeling good, you got to try and harness it and stay hot as long as you can," he said. "The last couple, I haven't felt too great, but I feel pretty close. I've kind of gotten some bounces go my way, some pitches that go my way, which definitely helps. I'm feeling pretty solid. I'm kind of getting back to where I'd like to be."

On Tuesday, Gallen got offensive support from Joc Pederson and Christian Walker.

Pederson and Walker hit back-to-back homers in the first inning and Walker added a two-run homer in the third off Nathan Eovaldi.

The homers were the first for Walker, since he returned from the injured list a week ago after missing more than a month with a left oblique strain. Walker went 3 for his first 15 after coming off the IL before squaring up the homers.

Though, he was more interested in talking about Gallen than himself postgame.

"He's fun to play behind," Walker said. "He's filling up the strike zone, you know, minimizing damage. He just never seems to give in. I'm just happy he's on my team."