The Mariners announced today that left-hander Rob Rasmussen has been designated for assignment. Rasmussen’s removal from the club’s 40-man roster creates space for right-hander Steve Cishek, whose two-year contract is now official.

The 26-year-old Rasmussen logged 15 1/3 innings in the Majors this season, and while he struck out an impressive 17 hitters in that time, he also walked eight men and yielded an alarming 17 earned runs as well. That marked his second stint in the Majors, although the first — four runs in 11 1/3 innings with the 2014 Blue Jays — was considerably more palatable.

Rasmussen was one of three pitchers that the Mariners acquired from the Blue Jays in exchange for Mark Lowe prior to the 2015 trade deadline. If his name sounds familiar, it’s due to the fact that Rasmussen, despite being just 26 years old and having 26 2/3 innings of Major League experience, has been traded an incredible five times. Originally a second-round pick by the Marlins in 2010, he’s been part of the return in trades for Carlos Lee and Michael Young (in addition to John Ely and Brad Lincoln).

In addition to his Major League work, Rasmussen has totaled 140 1/3 innings at the Triple-A level, where he has pitched to a collective 4.04 ERA with a 121-to-69 K/BB ratio. It should be noted that Ramussen’s work as a reliever at the Triple-A level has been wildly superior to his work as a starter. He posted a 6.46 ERA working primarily out of the rotation in 2013 (12 games, 10 starts) but has turned in ERA marks below 2.75 while working as a reliever in his past two stops at Triple-A.