Littell was added to the major-league roster ahead of Tuesday's doubleheader against the White Sox, Dustin Morse of the Minnesota Twins reports.
Littell is scheduled to start Game 2 of the doubleheader, although he figures to head right back to the minors following the conclusion of Tuesday's action. Through five appearances at Triple-A Rochester, he's posted a 2.57 ERA and 1.07 WHIP with a 30:10 K:BB over 28 innings.