After finishing his first major league camp Wednesday, Seattle Mariners rookie Yusei Kikuchi looked back fondly on the opening four weeks with his new team.

"I never felt like I wanted to take a break," said Kikuchi, who signed a four-year deal with the Mariners in January after being posted by Japan's Seibu Lions.

(Yusei Kikuchi pitches in an intrasquad game in Peoria, Arizona, on March 13, 2019.)

"For the entire month, I couldn't wait to start each day."

Kikuchi, formerly a top starter in Japan's Nippon Professional Baseball, has been touted as one of MLB's most promising new pitchers.

But the left-hander admitted feeling a little lost upon his arrival stateside, struggling with different practice methods, harder mounds and more slippery balls.

The dry air at the Mariners' spring training facility outside Phoenix, Arizona, also posed a challenge.

"I just tried to face everything constructively. I expected some difficulty adjusting to the ball, the mound and the environment, but I've made some progress."

After Kikuchi's final preseason start on Tuesday was rained out, the lefty faced 18 batters in an intrasquad game Wednesday, allowing four hits with five strikeouts and two walks.

Thirty players from the Mariners leave Thursday for the team's 2019 season-opening series in Japan next week against the Oakland Athletics. Kikuchi is scheduled to make his major league debut in the second game at Tokyo Dome on Thursday.

The 27-year-old said he intends to put on a good show for his home crowd.

"I think a lot of fans are looking forward to seeing me pitch, so I'll work hard to live up to that responsibility," Kikuchi said.

Kikuchi will be joined in Tokyo by veteran outfielder Ichiro Suzuki, whom Mariners Manager Scott Servais has indicated will be on the club's extended 28-man roster for the series. If Suzuki plays, it will be his first game in Japan since 2012.

The 45-year-old struck out in both of his plate appearances Wednesday during the Mariners' 8-4 spring training win over the San Francisco Giants, his seventh straight game without a hit.

Ichiro, who received a non-roster invitation to camp after signing a minor league deal, was considerably more downbeat than Kikuchi ahead of their Japan jaunt, having recorded just two hits in 25 at-bats this preseason.

"I want to be ready to appear (in the openers), fast," he said.

MLB announced Tuesday that former pitchers Masumi Kuwata and Masanori Murakami, the first Japanese to play in the major leagues, will toss the first pitches at a pair of exhibition games next week between the MLB clubs and the Yomiuri Giants and Nippon Ham Fighters, Shohei Ohtani's former team.

Former Mariners Kazuhiro Sasaki and Kenji Johjima will take part in Wednesday's first pitch ceremony, with Hall of Famer Rickey Henderson, who had four stints with the Athletics, standing in the batter's box.

On Thursday, former Athletics players Keiichi Yabu and Akinori Iwamura will feature in the ceremony alongside Mariners legend and Hall of Famer Ken Griffey Jr.