Mejia is expected to be recalled Saturday, Rhett Bollinger of MLB.com reports.
Mejia has already joined the Twins, but the team hasn't yet added him to the major league roster. An announcement should come later Saturday, with the expectation that Kennys Vargas will be the player optioned to free up a spot on the roster. Mejia, who was acquired from the Giants on July 28, holds a 4.66 ERA and 1.24 WHIP across 19.1 innings with Triple-A Rochester.