Humber, 26, was one of four prospects acquired from the New York Mets in the February 2008 deal for Johan Santana.
A first-round Draft pick by the Mets out of Rice University in 2004 and the third player taken overall that spring, Humber underwent Tommy John ligament-replacement surgery in 2005.
Working in long relief for the Twins to open 2009, he posted a 12.46 ERA in 4 1/3 innings before being designated for assignment on April 17 to make room for former Colorado Rockies relief prospect Juan Morillo off waivers.
Humber is expected to move back to a starting role for the Red Wings.
Lisa Winston is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.