PITTSBURGH -- When the Mariners signed Yusei Kikuchi to a four-year, $56 million contract ahead of the 2019 season, they knew that with flashes of success would come a need to learn and grow comfortable in his new environment.

That process is still ongoing for Kikuchi, who logged another shaky start as the season draws to a close. He lasted just four innings against the Pirates on Thursday at PNC Park, but Seattle was able to win in 11 innings, 6-5, thanks to Omar Narvaez delaying the third out in a rundown, which allowed Shed Long to score from third.

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Kikuchi showed his ability to induce weak contact when he’s in sync in the first inning, keeping his offerings low and changing eye levels. But he began to hang pitches in the middle of the zone in the second, helping the Pirates notch four doubles in a span of six batters and squander the Mariners’ early 4-0 lead.

“There wasn’t a big change from the first to the second,” Kikuchi said through an interpreter. “I think most of my pitches just got caught in the middle. That’s it.”

But he also demonstrated his composure, getting out of a bases-loaded jam against Pittsburgh’s No. 3 batter, Jose Osuna, in the fourth and final inning of his day as he was lifted after just 67 pitches.

“That was huge,” manager Scott Servais said. “… Getting through the fourth right there was great for Yusei, but I thought at that point, with kind of where he was and kind of how he was looking out there, just go to the bullpen. We had a lot of guys rested, and give those guys an opportunity to pitch today.”

As Kikuchi tries to end his rookie season in the Majors on a high note, he’s trending the wrong way; he allowed four runs over 10 innings in his first two starts this month, but he’s been knocked for nine runs in just 6 1/3 innings in his past two outings.

There will be time to address the bumps in the offseason, but Servais has his eyes on Kikuchi until his final pitch of the season in his planned next start, as the left-hander is on pace to reach the 32-start mark after never having more than 26 turns in a Japan Pacific League season.

“That was the whole key,” Servais said. “Let him through the year healthy, let him learn about the league and himself and the United States and everything that goes along with it, and then when we get done at the end of the year, what did we learn?”

Servais said of Kikuchi that “without question, he learned more than anybody else on our team this year.” On the field, the lefty has been forced to make adjustments to his routine, his gameplan and his mentality. Off it, he lost his father to begin the season, then became a father halfway through it. He’s pitched in front of a packed crowd in Tokyo, and even faced his first MLB plate appearance Thursday, reaching base on an error.

Through it all, Kikuchi is just trying to be his “best self” as he trots out to the mound every fifth day, both in his performance and the way he carries himself.

“There’s a big difference between here and Japan,” he said. “... But I’m learning every day and I’m studying every day.”

A career high for Long

Long is thriving from the leadoff spot from the Mariners, and he took another step forward with a career-best three hit game on Thursday. He also drew a walk and reached on an error in the 11th, setting himself up as the game-winning run despite an inning-ending double play.

The effort put Long’s batting line to 14-for-36 in an eight game span as the No. 1 batter, and it upped his OPS from .692 to .816 in that short time.

"Every game for me is important,” Long said, “but definitely these last few games of the year, I definitely want to finish strong, where my name is always in the back of their heads for any considerations for next year."