The Twins designated Megill for assignment Tuesday, Aaron Gleeman of The Athletic reports.
The move clears a spot on the 40-man roster for reliever Brock Stewart, whose contract was selected from Triple-A St. Paul. Megill holds an ugly 13.03 ERA and 16:13 K:BB over 9.2 innings with St. Paul this season. He'll now be subject to the waiver process but is expected to go unclaimed.