Japanese pitcher Hisashi Iwakuma will leave the Seattle Mariners at the end of this season in order to continue his playing career, the American League club said Tuesday.

The 37-year-old former All-Star right-hander has been seeking to return to the majors since he underwent shoulder surgery last September, but decided to turn elsewhere after being offered a coaching role with the Mariners.

(Iwakuma pitches against the Los Angeles Angels in May 2017)

"I was hoping to make my way back on the major league (roster) but I was told it won't happen this season. The decision was that I don't have enough outings in the minors and I'm not ready for the call-up," Iwakuma said.

"I was asked to support the team as a coach, not a player, in 2019. But I've finally regained my form and feel like I can pitch in a game. With Japan being a possible destination, I want to look for ways to continue playing. I'd like to think I'm still capable."

The Rakuten Eagles, where Iwakuma spent his last seven seasons in Japan, are already expressing interest in their 2005 Opening Day starter. Eagles' president Yozo Tachibana told reporters Wednesday in Sendai he is prepared to welcome him back to the team.

"He is a wonderful player who made history for the Eagles. If he's going to play in Japan, we'll make sure to do our research," Tachibana said.

Iwakuma, who has spent all six years of his major league career with the Mariners, has been sidelined since May last year with shoulder issues. The right-hander made only six starts in the 2017 season, his first in the majors without a win.

He returned to the Mariners on a minor league deal that allows him to rehab and work his way back without taking up a roster spot.

In his MLB career, Iwakuma has a 63-39 record with a 3.42 ERA over 150 games. He tossed a no-hitter against the Baltimore Orioles in August 2015, and was a Cy Young Award candidate in 2013.

Iwakuma said the long rehab process has been a valuable experience in his career, but he still feels "sadness and regret" about the way he will end his time with the Mariners.

Former Mariners teammate Ichiro Suzuki, now a special assistant to the club's chairman, wished Iwakuma well as he pursues opportunities in Japan but also said he is sad to see him leave.

"I wish we could've played together one last time. This is an unexpected goodbye," Suzuki said.

"I heard he was recovering and I thought I would be able to see him pitch (in the majors) again. I'm surprised with his quick decision to go back (to Japan)."

Before he made the jump overseas, Iwakuma had a standout career with the Kintetsu Buffaloes (now Orix Buffaloes) and Rakuten in Nippon Professional Baseball, where he went 107-69 with a 3.25 ERA in 226 games between 2001 and 2011.