Seattle acquired Schugel on Wednesday and designated for assignment left-handed pitcher Tyler Olson.
Schugel, 26, made his major league debut last season with the Diamondbacks. Schugel made five appearances during two stints with Arizona. He split most of the season between Double-A Mobil and Triple-A Reno and was 9-9 with a 4.84 ERA combined in both stops. Schugel was originally a 25th-round pick of the Angels in 2010.
Olson, 26, started last season in the majors with Seattle and appeared in 11 games before landing on the disabled list. Olson was 1-1 with a 5.40 ERA with the Mariners.