Corey Kluber showed signs of his former Cy Young form Tuesday.

One of three Indians rehabbing with the RubberDucks — Dan Otero and Tyler Olson also pitched — Kluber also showed he’s still a few weeks away from rejoining the team.

He retired the first 10 Trenton Thunder batters he faced in his second rehab start of the season and first with the Ducks.

In the fourth inning, though, Kluber appeared to tire and gave up a home run to Kyle Holder and a base hit to Kellin Deglan.

“I felt good,” he said. “I had a lot easier time getting into the flow of the game. Last time, it was weird. I felt like I continued to fine-tune some pitches. I’m just trying to get ready.”

The right-hander has been on the 60-day injured list since May 2 with a right ulna fracture, and Indians brass have said they don’t expect him back until the end of August or the beginning of September.

The 33-year-old finished the last of his 65 pitches in the cage, but had flashes of brilliance against the Thunder.

Kluber allowed just four hits and one walk with six strikeouts in four innings, throwing 36 strikes in 60 pitches. He hit 93 mph twice.

“It’s just part of the process continuing,” Kluber said. “I wouldn’t say there’s anything glaring. I think that, like I said earlier, I got into the flow of the game quicker. It didn’t feel like I was in that bullpen mode so to speak at the beginning.”

Before his injury, Kluber had a bit of an issue with his control, walking 15 in 35 2/3 innings. By way of comparison, he walked only 34 batters in 215 innings last season.

Against the Thunder, he went to a three-ball count five times, but only lost one batter after that.

That’s a better showing than his first rehab start in which he allowed two runs — both home runs — on two hits and struck out two in three innings with Triple-A Columbus.

“I’m just taking it start to start,” Kluber said. “I don’t have a way to grade it as far as where we are. Maybe I was a little fatigued, but I think that’s part of it. It’s getting stretched out.

"You get into points where you get past where it was comfortable the last time and you have to push through a little bit. That’s where you can get built up.”

Otero made his ninth rehab start of the season and third with the RubberDucks since right shoulder inflammation took him away from the parent club on May 31.

In his July rehabs, he had a solid one-inning, one-hit outing, but then got rocked, giving up three home runs in an inning against Binghamton.

Otero, who is scheduled to make at least one more rehab appearance with Columbus, was much better against Trenton on Tuesday.

The right-hander issued a one-out walk to Brandon Wagner, but induced Rashard Crawford to fly out to center and Hoy Jun Park to ground out to first in his inning of work.

“I feel healthy,” Otero said. “I think last time I was still fighting through some nagging stuff. I didn’t know it at the time. I had no previous maybe injury or rehab to look at. I pitched through a lot of discomfort so I thought it was something I needed to pitch through. It ended up being a little more serious than I thought. Finally, I had to get shut down after my second outing in Columbus.

"I think now we have a really good handle on what I need to manage. I’m feeling healthy, feeling good and I feel like I’m ready to go.”

Olson, who has been on the disabled list since Aug. 2 with shingles, pitched two-thirds of an inning. The left-hander opened the sixth inning by allowing a single to Holder and walking Ben Ruta, but struck out Chris Gittens and Deglan to finish his night.

“I felt good,” Olson said. “I feel like I figured some things out. I made some adjustments. I’m pretty good with where I was at.”