The Mariners acquired left-handed pitcher Roenis Elias from the Red Sox on Monday in exchange for a player to be named later or cash considerations.
Elias, 29, will report to Triple-A Tacoma.
Seattle originally signed Elias as a free agent out of Cuba in 2011. He pitched in 51 games (49 starts) and posted a 3.97 ERA with the Mariners from 2014-15 before he was dealt to the Red Sox with right-hander Carson Smith for right-hander Jonathan Aro and left-hander Wade Miley in December 2015.
Elias played sparingly in the big leagues with Boston, appearing in just four games over the past two seasons. He spent the majority of 2017 on the disabled list with a strained right oblique.
Elias was 1-0 with one save and a 1.23 ERA in 7 1/3 innings for Triple-A Pawtucket this season. He is 15-21 with a 4.20 ERA (134 earned runs in 287 innings) with 244 strikeouts and 114 walks in 287 innings over 55 career Major League games, 50 of them starts.