PITTSBURGH — Derek Shelton emerged from the dugout at sweltering PNC Park and trotted toward the mound to take the ball from Mitch Keller early in the eighth inning on Wednesday.

A smattering of boos greeted the move after Keller had spent most of the afternoon dominating the Reds with remarkable efficiency.

Keller, however, didn't say a word after issuing a leadoff walk in a scoreless game. Sure, he'd thrown 83 pitches over seven-plus innings, but with temperatures in the mid-90s, Keller admitted it felt more as if he'd tossed 150.

So he didn't plead his case. There was no need anyway. Keller knows as well as anyone what's lurking at the back end of a bullpen that's becoming dominant. Colin Holderman retired the next three batters to get out of the eighth unscathed.

Bryan Reynolds' solo shot in the bottom of the eighth gave the Pirates the lead. David Bednar worked a perfect ninth for his 16th save as Pittsburgh took two of three from the Reds in a series that offered a glimpse of what its staff could become as spring turns to summer.

Electrifying rookie Paul Skenes and three relievers held the Reds to one run in a victory on Monday . Bailey Falter pitched seven solid innings in a losing effort on Tuesday. Keller, Holderman and Bednar limited the Reds to four base runners, none of whom made it to third.

“I don’t know if we’ve pitched better than we did in this series,” Shelton said.

It's becoming a bit of a habit. The shutout was the fourth tossed by the Pirates in June. They've allowed four runs or fewer in 12 of their 17 games this month, buoyed by not just a rotation that boasts Skenes, Keller and Jared Jones but a bullpen that has started to figure things out after a sluggish start.

Not bad considering the Pirates are essentially short a starter at the moment with Marco Gonzales, Martin Perez and Quinn Priester all on the injured list at the moment.

“Everyone’s vibing and gelling together,” Keller said. “Everyone’s helping each other out which is really cool to see. Picking up little tidbits from someone here and there. It’s really cool.”

While Skenes is 4-0 with a 2.29 ERA and 53 strikeouts in 39 1/3 innings during his seven starts — starts that are increasingly feeling like events in a city where the Pirates have largely been an afterthought for the past half-decade — he's hardly doing it alone.

Keller, who signed a $77 million contract extension in February after being an All-Star last season, is 6-1 with a 1.53 ERA since May 1. Falter's ERA is 3.74, a full run below his career average coming in. Bednar, slowed by a lat injury that forced him to miss basically all of spring training, converted 10 saves since the start of May. Holderman has allowed just two runs in 26 appearances in a setup role.

Their emergence has helped the Pirates stay in the mix of an underwhelming NL Central despite an offense that is struggling to produce consistently. Pittsburgh is in the bottom third in the majors in most major offensive categories, including runs (22), homers (23rd) and OPS (28th).

“Yeah man, (the pitching is helping) us out a lot, especially today,” Reynolds said. "Mitch puts up a zero all the way to the eighth and just hands it off. Helps the offense a little bit. Takes a little pressure off.”

It helps to have a staff that seems to have taken ego out of the equation. There is a free exchange of ideas — from the starters to the relievers — on everything from sequencing to pitch grips to tips on how to rest and recover.

Keller makes it a point to tell Bednar regularly that he likes Bednar's splitter to help give him confidence. Holderman has been experimenting with the delivery of his sinker, willing to give just about anything a shot.

“There's a lot of smart guys in this room,” Holderman said.

Guys who are regularly giving opponents plenty to think about. Cincinnati manager David Bell watched emerging Reds ace Hunter Greene shut down the Pirates over 6 1/3 masterful innings only to be outdueled by Keller.

“Keller I think executed every single pitch he threw today,” Bell said. "Today was a tough day with Keller, Holderman and Bednar, they executed their pitches and they have really great stuff to go with it.”

Pittsburgh plans to rely on the staff heavily as it tries to gain traction to seriously contend for a postseason spot for the first time since the club won 98 games in 2015.

This group is not that group that featured proven veterans such as A.J. Burnett and J.A. Happ to go with a young Gerrit Cole. The current Pirates are still under .500 as July 4 approaches.

Still, there is an optimism in the clubhouse that's been missing for a while. It's creeping back in with impressive outings from the guys in charge of throwing the ball.

“We've got a lot of dudes in here with good stuff,” Holderman said. “And the further we get in the season with some guys that don't have that much experience in the big leagues, they're only going to get better and I think our pitching is going to last pretty deep into the season.”