The Mariners designated Margevicius for assignment Thursday, Daniel Kramer of MLB.com reports.

Margevicius' removal from the 40-man roster clears a spot for Danny Young, whose contract was selected from Triple-A Tacoma. After failing to break camp with the big club, Margevicius had been a member of the Tacoma rotation, posting a 12.75 ERA and 2.58 WHIP across 12 innings through four starts.