Tanaka went 78–46 with a 3.74 ERA in seven seasons with the Yankees.
After seven seasons with the Yankees, free-agent pitcher Masahiro Tanaka is returning to Japan to play for the Rakuten Golden Eagles in the Nippon Professional Baseball League.
Tanaka revealed his decision on Twitter in a message to his "beloved fans."
"I have decided to return to Japan and play for the Rakuten Eagles for the 2021 season," he said. "I wanted to make sure and touch base with you, and thank you for all the love and support you have given me for the past 7 seasons."
"I feel extremely fortunate for having the opportunity to take the field as a member of the New York Yankees, and play in front of all you passionate fans. It has been an honor and a privilege! Thank you so much!!"
Terms of Tanaka's deal have not been released, but the Eagles announced the right-hander's return on social media, saying "Welcome home our hero."
Tanaka, 32, spent seven seasons with the Eagles, going 99–35 with a 2.29 ERA and 1,238 strikeouts before Rakuten posted him to make him available to play overseas. In 2014, he signed a seven-year, $155 million deal with the Yankees, and became one of the most consistent members of their starting rotation.
Tanaka missed some time in the shortened 2020 season after being hit in the head by Giancarlo Stanton's line drive during a simulated game in early July. In 10 starts last year, he posted a 3.56 ERA with 44 strikeouts.
After discovering a partially torn ligament in his elbow during the 2014 season, the Yankees tried to give Tanaka extra rest between some of his starts. In 174 career appearances with New York, he went 78–46 with a 3.74 ERA and delivered some of his best work during the playoffs.
Over 54 postseason innings, Tanaka had a 3.33 ERA, 44 strikeouts and 15 walks in 10 starts.
His decision to return to the Eagles isn't too surprising given the current state of MLB's free-agent market and the Yankees' recent transactions. Earlier this month, the club acquired starter Jameson Taillon in a trade with the Pirates and signed pitcher Corey Kluber to a one-year deal worth $11 million.