PHOENIX -- In just one-third of an inning, Shane Bieber’s outing went from terrific to having a nightmare ending.

Over the first seven frames, Bieber allowed four hits and only made one bad pitch, a knuckle curveball high in the zone that Christian Walker slugged for a two-run opposite-field homer in the fourth inning, tying the game at 2.

Then the eighth inning happened. With the score tied, Jake McCarthy sailed a 2-2 slider over the right-field fence for a 3-2 lead. Three batters later, rookie sensation Corbin Carroll added some insurance by launching a Statcast-projected 110.1 mph, 426-foot two-run homer.

That inning resulted in a 6-3 loss to the D-backs Saturday night under the roof at Chase Field. The Guardians have now lost four of their last five games.

“I thought he pitched his heart out, but [it’s] a shame that the line at the end of the night is not going to make it look [it],” Guardians manager Terry Francona said of Bieber. “He hung a breaking ball to Walker, who has just tormented us. … Man, it's a shame because he really pitched well.”

D-backs manager Torey Lovullo echoed Francona’s words about Bieber.

"When you're going against a pitcher of Bieber's ability and with the quality stuff that he has, you're just trying to figure out how you're going to grind down and grind out your day, and hopefully he doesn't have his best stuff,” Lovullo said. “I think he had good stuff, and we just hung in there."

It wasn’t the result anyone on the Guardians wanted, but if there was anything positive to come of it, the bullpen finally got the rest it needed.

In the prior four games, Cleveland relievers pitched 18 2/3 innings and likely would have gotten some more rest Friday -- until Triston McKenzie was scratched from his start and eventually placed on the 15-day injured list with a right elbow sprain. Bieber’s deep run finally decreased the bullpen's workload.

“I want to be in there as long as I can, [I’d] throw 200 pitches if I could,” Bieber said. “The 200th pitch is not going to be as good as pitch No. 1, but the answer will always be the same. I always want to be in there, I always want to extend my outings and get the team the best start possible. I just wasn't able to do that there in the eighth.”

Asked if he felt any extra pressure knowing he needed to get deep into the game, Bieber said, “No, I expect myself to go deep whatever the situation is. I found myself in a good position to do that and tried to get a little bit more and got bit for it. So it's going to happen, and through a long healthy career, you're going to have some frustrating ones, and this is definitely up there.”

For the most part, Bieber did his job, but the offense never really gave him the run support he needed, which has been a trend on this road trip.

The Guardians rattled up D-backs starter Tommy Henry and loaded the bases in the first inning. They only managed to leave with a one-run lead, which was produced on a walk by Andrés Giménez. 

The offense wasn't nonexistent, but the batters just weren’t clutch. Steven Kwan and Amed Rosario, the Guardians' Nos. 1 and 2 hitters, combined for eight hits. Giménez hit a solo home run in the third. The Guardians left 10 on base and had runners in scoring position with two outs in four innings. But none of that matters if the runners don’t cross home plate.

“We started some rallies with two outs, which that's good,” Francona said. “But we just didn't have a lot of wiggle room, and we couldn't get a big hit."

It also didn’t help that the D-backs' defense shined.

"I really feel like José [Ramírez] did what he had to do. I think [Ketel] Marte made a really good play over his shoulder. Walker made a really good play on the line,” Kwan said. “I mean, they hit the ball hard. They just happen to field them, and I think in a bigger sample size, those probably get through, we score the runs and it's a closer game. So they played well today."