The Twins will call up righthanded reliever John Curtiss, a source with knowledge of the move confirmed.
Curtiss, 24, would become the 35th pitcher to take the mound for the Twins this season, the franchise-record 50th player to wear the uniform
The 2014 sixth-round pick had a combined 1.28 ERA in 39 games between Class AAA Rochester and Class AA Chattanooga this year. He has 68 strikeouts in 49 1/3 innings, including 33 in 24 1/3 innings at Rochester, where he had a 1.85 ERA.
Tim Melville, who was knocked out in the fourth inning of Monday's doubleheader opener at Chicago, was designated for assignment.
Curtiss should be in uniform for Wednesday night's game against the White Sox.