PHOENIX -- Tuesday wasn’t the best night for the Dodgers. A third-inning error proved costly and negatively impacted Tony Gonsolin’s start. The offense hit into five double plays. Brusdar Graterol gave up a tie-breaking two-run home run to David Peralta in the eighth that lifted the D-backs to a 5-3 win.

But Tuesday was also a day for optimism for Los Angeles. And that’s because it received several in-person reminders that its pitching staff -- which has been the best in MLB early this season -- isn’t even at its full potential yet.

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Earlier in the day, the Dodgers were visited by three pitchers who have been rehabbing injuries at the club’s Camelback Ranch facility in Glendale, Ariz. Dustin May, Danny Duffy and Victor González all moved their respective throwing programs to nearby Chase Field in downtown Phoenix for a day, spending some time with their teammates and coaches in the process.

Los Angeles has the makings of a solid pitching staff with the hurlers it currently has on the injured list. In addition to May, Duffy and González, the club has also been without other key arms, such as David Price, Blake Treinen, Andrew Heaney, Tommy Kahnle, Caleb Ferguson and Jimmy Nelson.

• Injuries & Moves: Latest on May, Price, Treinen, more

However, the most impactful midseason addition that the Dodgers could be getting back from that group is May. And it was evident how thrilled the team was to see the 24-year-old right-hander by how many players came out to the bullpen to watch him throw Tuesday afternoon.

“It excites me,” manager Dave Roberts said. “There was a good contingent representing us watching Dustin, which obviously speaks to our excitement. He’s going to be a weapon.”

When healthy, May has been a tremendous asset to the Dodgers’ rotation over the previous three seasons, during which he posted a 2.93 ERA in 31 games (19 starts). He had a 2.74 ERA and 0.96 WHIP through five starts in 2021, before undergoing Tommy John surgery last May.

May is still targeting the final third of the season for a potential return. He’s thrown nine bullpen sessions -- each of which has been about 25-30 pitches -- and he’s just now beginning to work in non-fastball pitches.

It will still likely be close to a month before May throws live batting practice, though, as he doesn’t anticipate doing that until around late May. Then, he’ll get built up as a starter, according to Roberts.

“Facing hitters will probably be the biggest milestone, I think,” May said. “Because that’s when you get the adrenaline back, you have to actually get somebody out in front of you and you actually have to make sure your pitches are where you want them to be.”

As for joining Los Angeles’ potent pitching staff in late summer/early fall, May can’t wait.

“I feel like I’m missed. I hope I am, because I want to be back,” May said. “I’m excited, hopefully they’re excited as well.”

They should be, because the unit has already been on a roll even while short-handed. The Dodgers lead MLB with a 2.21 ERA and 0.91 WHIP. Their starting rotation ranks second in the Majors in those marks (2.21 ERA and 0.99 WHIP).

Los Angeles’ top of the rotation is strong with Walker Buehler, Clayton Kershaw and Julio Urías leading the way, but Gonsolin has been an important early contributor, too. The right-hander allowed three runs (two earned) in four innings on Tuesday and has a 1.59 ERA in four starts.

Gonsolin looked dominant at the beginning of his outing vs. Arizona, retiring six of his first seven batters to extend his scoreless streak to 14 innings. But all three runs he allowed came in the third, with a pair scoring on a play in which second baseman Gavin Lux threw a ball wide of first baseman Freddie Freeman.

Still, there were positives to take away from Gonsolin’s outing, such as some improved command.

“I thought the fastball was decent today, thought I executed them a little bit better than the last couple outings, which was nice to see,” Gonsolin said. “I can definitely do a little bit better job, though.”

After Tuesday’s game, May exited the visitors’ clubhouse, equipment bag in hand, and waved goodbye to some staff members in the workout area. One of the next times he sees the team, he could be joining Gonsolin and his other rotation mates to provide a big late-season boost.

And at that point -- with more returns likely to take place between now and then -- the Dodgers’ pitching staff could be even better.