GOODYEAR, Ariz. -- Two key pieces of the Mariners’ pitching future were on display Thursday and the results were encouraging, at least after new Japanese lefty Yusei Kikuchi survived a rough first inning and a Yasiel Puig comebacker off his thigh in Seattle’s 11-3 Cactus League win over the Reds.

Kikuchi limited the damage to one run after getting into a one-out, bases-loaded jam in the first frame, then he shook off a leadoff homer in the second as he settled in to allow just the two runs in four innings while continuing to adjust to life in the Majors.

That outing came on the heels of an impressive 3 2/3 scoreless innings by new No. 1 prospect Justus Sheffield in an afternoon intrasquad game at the Peoria Sports Complex against a lineup loaded with some of Seattle’s best veteran hitters.

Kikuchi figures to be an instant factor for the Mariners as he’ll be in the rotation that opens the season in his native Japan against the A’s in less than two weeks, while Sheffield clearly is just waiting for his call whenever Seattle’s brass deems him ready.

Kikuchi is learning on the fly in his new environment, and the key lesson on Thursday was the Reds -- whom he’d held scoreless in two sharp innings in his Cactus League debut 10 days earlier -- were sitting on his fastball-slider combination early.

After Derek Dietrich’s leadoff homer in the second, the 27-year-old southpaw started mixing in more curveballs and shut down the Reds the rest of his outing while keeping the ball primarily on the ground.

“That’s a learning point from today, pitching a little more off my curveball and making them change speeds,” Kikuchi said through interpreter Justin Novak. “Compared to my first two starts, I was a little more scattered and didn’t have my best stuff, but I was able to grind through and I’m proud of myself for only allowing the one run in those first two innings.”

Mariners manager Scott Servais noted every day is a lesson at this point for the three-time Japanese All-Star.

“I was really happy with the way he threw tonight,” Servais said. “Every time out there’s he’s learning more, whether it’s his relationship with the catcher or what the other teams are going to do against him. He’s continuing to really progress nicely.”

Sheffield was on his own learning curve earlier in the day in a controlled situation that allowed teammates Dee Gordon, Mitch Haniger, Edwin Encarnacion and Ichiro Suzuki – who have 16 All-Star appearances between them -- to face him in each of his three innings as they looked to get extra at-bats.

Sheffield allowed just two hits with no walks and six strikeouts, including punchouts on five of the first eight batters he faced.

“When you’re starting, you want to face a lineup three times, and I got to do that with just three innings, so that was cool,” Sheffield said of the informal setting. “I felt great. I was impressed with my changeup again today and content with my slider. So it was a good day.”

Sheffield, acquired in the James Paxton trade from the Yankees in December, has impressed his new club with his poise and quality pitches.

With Paxton pitching on the overhead TV in his office from a Grapefruit League game in Florida, where he fired 3 1/3 scoreless innings against the Phillies, Servais praised the efforts of his own new 22-year-old prodigy.

“We’re working on a few things, but all three [of Sheffield's] pitches are working,” Servais said. “Really good slider to finish off some guys. I really like where he’s at. The slider is certainly an out pitch. It was nice to see him throw a few for strikes. I know he likes to take it down and in to the righties. He can put them away with that pitch, but you also have to throw it for a strike, which he did today. It was good to see.”

Haniger was equally effusive.

“The fastball command is there,” said Haniger, who went 1-for-3 with a single and strikeout against the youngster. “Really good changeup, I know that’s a pitch he’s been working on, but that’s a plus changeup for any lefty starter, especially. And he’s got that slider in his back pocket too, and it’s really good. If he can locate and mix those three, he’s going to be really good for us.”