Miranda signed a one-year, $800,000 contract with the Korea Baseball Organization's Doosan Bears on Wednesday, Jee-ho Yoo of the Yonhap News Agency reports.
Miranda was released by the Mariners on Wednesday, Ryan Divish of The Seattle Times reports.
Miranda was sent back to Triple-A Tacoma on Wednesday.
Miranda allowed one earned run on six hits while walking four and striking out five across five innings Tuesday against the Astros. He did not factor into the decision.
Miranda was called up from Triple-A Tacoma ahead of his start Tuesday against the Astros.
Miranda isn't expected to be recalled from Triple-A Tacoma to start Wednesday against the Royals after the Mariners adjusted their rotation following a postponement Sunday, Shannon Drayer of 710 ESPN Seattle reports.
Miranda, who's slated to start next Wednesday's game against the Royals, recorded five strikeouts and allowed five runs (one earned) on six hits and two walks over five innings in High-A Modesto's win over the 7-5 win over Lancaster on Friday.
Miranda will be called up from Triple-A Tacoma and take the hill when the Mariners first require a fifth starter April 11 against the Royals, Greg Johns of MLB.com reports.
The Mariners optioned Miranda to Triple-A Tacoma on Sunday, TJ Cotterill of The Tacoma News Tribune reports.
Miranda is competing for a spot in the back-end of the team's rotation this spring, but will likely wind up being utilized as a depth piece out of the Mariners' bullpen in 2018, Shannon Drayer of mynorthwest.com reports.