SEATTLE -- A rebuilding Mariners team added a strong piece to its pitching rotation as Japanese standout Yusei Kikuchi finalized a deal on Wednesday that will keep him in Seattle anywhere from three to seven years, depending on how it plays out.
The Mariners didn't release the financial terms of the contract and are listing it as a four-year contract, though a source confirmed to MLB.com that the unique deal is for $43 million over an initial three years, with a $13 million player option for 2022. But the option can potentially be replaced by an additional four-year, $66 million extension by the club that would convert the deal to seven years total.
If Kikuchi declines the option for 2022 and the Mariners don't pick up the four-year extension, he would become a free agent at that point. If Kikuchi stays all seven years, he'd earn a total of $109 million, or about $15.6 million per season.
• Get to know Kikuchi
The 27-year-old Kikuchi was one of the prime free-agent starters available this offseason, and he had to sign with an MLB team by 2 p.m. PT on Wednesday or he would've had to return to the Seibu Lions, his team in Japan's Nippon Professional Baseball League, for the 2019 season. Under the new Japanese posting system, the Mariners will pay his former club a release fee that will be a percentage of his contract.
Mariners general manager Jerry Dipoto has traded away a number of prominent veterans this offseason while reworking his roster with younger prospects in taking aim toward a push in 2020-21, but he believes Kikuchi can be part of that future wave of talent.
"Yusei's combination of character, talent, experience and relative age made him a primary target in our roster building plans," Dipoto said. "He is an exciting young pitcher with the ability to impact the Mariners, both in the present and future."

The Mariners will introduce Kikuchi at an 11 a.m. PT press conference on today that will be streamed live on Mariners.com.
Dipoto sees Kikuchi as being of similar age and remaining team control as All-Star right fielder Mitch Haniger, newly acquired center fielder Mallex Smith and fellow left-handed starter Marco Gonzales, who are part of the new core he's looking to build around after adding a number of young prospects via trades this offseason.
At this point, the Mariners' rotation for 2019 figures to include Gonzales, Kikuchi and veterans Felix Hernandez, Mike Leake and Wade LeBlanc.
But several promising prospects are now waiting in the wings to join Gonzales and Kikuchi in the longer term, including 22-year-old Justus Sheffield, who is ranked as the club's No. 1 prospect by MLB Pipeline, after he was acquired from the Yankees in a trade for James Paxton.
Justin Dunn, a 23-year-old right-hander, was the Mets' top pitching prospect before being acquired by Seattle in the Robinson Cano/Edwin Diaz deal, and 25-year-old right-hander Erik Swanson also figures into the mix after coming over from the Yankees in the Paxton deal.
Kikuchi went 69-45 with a 2.69 ERA over seven seasons in Japan. He features a mid-90s fastball and quality slider among his four-pitch repertoire.

"He's very good. His performance speaks for itself," Dipoto said at the Winter Meetings two weeks ago. "He's got real stuff, and he's had a lot of success in Japan. We've probably scouted him as much as any player in [Nippon Professional Baseball] in recent years, just because he's been there for a number of years and we've had a lot of volume."
The Mariners made a big push for two-way star Shohei Ohtani last offseason before he signed with the Angels. But Seattle has a strong history of Japanese players, and the club's majority ownership was the Japanese-based Nintendo of America from 1992-2016.
The Mariners have had at least one Japanese player on their roster every year since 1998, including Ichiro Suzuki, Hisashi Iwakuma, Kenji Johjima, Kazuhiro Sasaki, Shigetoshi Hasegawa, Norichika Aoki, Munenori Kawasaki and Mac Suzuki.
Iwakuma spent the past seven seasons as a starting pitcher with Seattle, though he dealt with right shoulder issues in 2018 and has returned to Japan to finish out his career.

The Mariners don't have any Japanese players on their 40-man roster, though Ichiro closed out last season as a special assistant to the club's chairman. He will be invited back to Major League camp this spring and given a chance to earn a roster spot at least for the two-game season-opening series in Tokyo against the A's in March, when the club can carry two extra players.
That strong Japanese connection figured to be a plus in recruiting Kikuchi.
"I think so," Dipoto said at the Winter Meetings. "We're a great market for any player, really, but specifically a pitcher. And specifically a pitcher from Japan, because we offer a lot of comforts that make us unique among the MLB markets with our great diversity in the city, and the way our market has taken the star players from Japan and really maximized their potential, whether that's from a marketing perspective or within the community.
"Those players -- whether Kaz Sasaki, Ichiro, Kuma -- those players turned into stars. And some of that comes from the market. We do have a great Japanese-American community. We are heavy in our influence organizationally, whether it was Nintendo or those great players and the way they're still connected in some way to the organization."