PHOENIX -- The Diamondbacks weren't waving the white flag on the 2014 season, but when they designated for assignment struggling former closer J.J. Putz for assignment on June 20, it signaled the start of a new era.
"As far as the relief pitching goes, we decided to move on in that area and (go with) some of the kids in the minor leagues where our depth is," D-backs manager Kirk Gibson said. "The guys at the lowest levels are progressing, and that's kind of affected us at this level."
A day earlier, hard-throwing reliever Matt Stites was called up from Triple-A Reno. Rookie Evan Marshall already had been up for more than a month. With this season beyond saving, the D-backs are embracing at least a part of their bullpen's future, giving Marshall and Stites extended opportunities to establish themselves as big-league relievers.
"Both those guys have been pretty good for us," Gibson said. "We've got to keep them healthy and watch how we use them."
Marshall and Stites very well could be the next setup-closer duo, a la David Hernandez and Putz, even if it doesn't happen this season or next. The D-backs already have eighth- and ninth-inning guys in Brad Ziegler and Addison Reed. Ziegler is under contract for one more season, and Reed, despite his struggles in the closer's role this season, is just 25.
Hernandez, once seen as the closer in waiting, is recovering from Tommy John surgery and could return to form but will turn 30 next season and will become increasingly expensive. Soon, it appears, a window will be open for Marshall and Stites.
Marshall already is handling the seventh-inning duties, and has been more than serviceable. In 24 appearances, 18 of them scoreless, Marshall owns 11 holds and a 3.68 ERA -- inflated last month from 1.96 by a three-run, no-out appearance.
"He's learned some lessons along the way," Gibson said. "He's getting smarter with what he does. He's learning how to make in-game adjustments."
Marshall said he had to adjust to the less-scripted nature of the majors. In the minors, warming up meant he was going in. Here, things can change quickly, so Marshall had to learn to warm up only so much before getting the call.
"The biggest difference is that when things go south they can go south really fast," Marshall said. "A one-run inning can turn into a four-run inning in just a couple of batters, so you really have to just make sure that doesn't happen."
Prior to his promotion, corresponding with a Putz trip to the disabled list, Marshall had allowed one run in 14 appearances with Reno.
Marshall's role wasn't clearly defined when he arrived -- "Just make sure you're ready to throw," he recalls being told -- but he slid quickly into his seventh-inning role, and his promotion freed up a spot in Reno, which Stites filled.
Acquired when the D-backs traded Ian Kennedy to the Padres last season, Stites had a limited track record in the organization. He needed an appendectomy right after being traded and didn't pitch for the organization in 2013. After a Fall League stint, he was assigned to Double-A Mobile, a step below where he'd hoped to be.
"I knew if I pitched how I did with San Diego -- just pound the strike zone, not walk guys, get guys out -- that would eventually take care of itself," Stites said.
Stites made just 12 appearances with Mobile before Marshall's promotion prompted his move to Reno, where he posted a 2.25 ERA with 15 strikeouts in 16 innings. With a four-seam fastball that reaches the upper 90s, Stites dominated the minoirs. But the big leagues are a different animal.
"He kind of realizes he's got to be a little more selective with where he throws the ball," Gibson said. "You can't just throw 97 and think you're going to blow it by everybody. He's got a good change-up and a good slider as well. So he's got weapons, he's got pitches. He's just starting to figure it out."
Gibson has mostly resisted discussing Stites as a potential closer, but the team clearly believes he has the stuff to be one. In the minors this year, he converted all 15 of his save opportunities. For now, Stites is a utility reliever, pitching anywhere from the sixth to ninth inning.
"I didn't really have any expectations just knowing what I had been doing was already taken care of here," Stites said. "So I came into it with an open mind, and it's worked out well."
In 11 appearances, Stites has a 2.61 ERA but has allowed five walks over 10 1/3 innings. He made two scoreless appearances against the Marlins this week, the first of which featured a three-pitch strikeout of NL home run and RBI leader Giancarlo Stanton.
Stites doesn't have his sights set on Reed's or anyone else's job, though. He's content pitching wherever he's needed and seeing where things go.
"I would like to (close) again, but if it never happens and I have a role in the seventh or eighth inning or even what I'm doing now that's fine with me," Stites said. "It's been great. I'd like to stay for a while."
Marshall sees himself doing in the future what he's doing now, handling the seventh or eighth inning and helping get the ball to the closer. Neither he nor Stites seem headed back to the minors any time soon. As the D-backs retool before the trade deadline and into the offseason, both will undoubtedly be part of the plans.
There's more relief in the pipeline as well, including 2012 third-round draft pick Jake Barrett and 2013 seventh-round pick Jimmie Sherfy.
The timeline remains yet unclear for how the D-backs bullpen -- or the rest of the roster -- will evolve further, but with Marshall and Stites staking their claims in the majors, the future is now.
"They should have good futures, good careers with us," Gibson said. "I think we're encouraged by what we've seen."
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