The Seattle Mariners on Wednesday announced the signing of Japanese left-hander Yusei Kikuchi, delivering a 2019 surprise for a team that has traded a number of foundational pieces already this winter.

The novel contract could see Kikuchi in Seattle for as few as three years and as many as seven, according to sources. The base deal is for three years and $43 million. Following the 2021 season, the Mariners can trigger a four-year, $66 million extension. If they decline to do so, Kikuchi either can trigger a $13 million option for the 2022 season or elect free agency. The deal guarantees $56 million and can be worth as much as $109 million.

Kikuchi, 27, was among the best free-agent pitchers left on the market and drew widespread interest before selecting the Mariners.

"Yusei's combination of character, talent, experience and relative age made him a primary target in our roster building plans," Mariners general manager Jerry Dipoto said in a statement. "He is an exciting young pitcher with the ability to impact the Mariners, both in the present and future."

In eight seasons with the Seibu Lions, Kikuchi posted a 2.77 ERA with 903 strikeouts in 1,010⅔ innings pitched. He was at his best in 2017, when he threw four shutouts en route to a 1.97 ERA and runner-up finish for the Sawamura Award, the Japanese equivalent of the Cy Young. With a fastball in the low 90s that ticks up to 95 and an above-average slider, Kikuchi followed in 2018 with a solid, if not as spectacular, season.

The Mariners were sold nevertheless, inviting Kikuchi to Seattle to finish the deal. It wasn't the sort of move consistent with their previous rejiggering this offseason, and yet Dipoto has stated a desire to compete again by 2021, according to sources, and a deal with Kikuchi will place him in Seattle in that window.

Over the winter, Dipoto has traded ace James Paxton, star closer Edwin Diaz, second baseman Robinson Cano, shortstop Jean Segura, catcher Mike Zunino and reliever Alex Colome for a mixture of prospects and salary relief. Seattle continues to shop designated hitter Edwin Encarnacion, sources said, in hopes of finding a team that will absorb at least some of the $25 million Seattle owes him. He arrived in a contract-swap deal that sent Carlos Santana -- who had come back in the Segura deal -- to the Cleveland Indians.

Kikuchi will join -- and possibly head -- a rotation that includes Marco Gonzales and Mike Leake, the latter of whom they have tried unsuccessfully to trade, sources said. A number of options exist for the last two spots, should the Mariners go with a traditional rotation, including Felix Hernandez, Wade LeBlanc, Roenis Elias and Justus Sheffield, the main return they received from New York in the trade that sent Paxton to the Yankees.

With Kikuchi headed to Seattle, the free-agent pitching crop has thinned significantly. The best option is considered left-hander Dallas Keuchel, with a drop to Wade Miley and Gio Gonzalez. Among the top right-handed starters available: Ervin Santana, Clay Buchholz and Jeremy Hellickson.